Microsoft Access

1

CHNG 1

GII THIU V MICROSOFT ACCESS 1.1 GII THIU MS - ACCESS 2003

1.1.1 Ngun gc v cng dng

Microsoft Access 2003 l chng trnh ca b ng dng vn phng Microsoft Office 2003 chy trn mi trng Windows. y l phn mm thuc h Qun Tr C S D Liu Quan h (Relational Database Management System RDBMS) gip qun l, bo tr v khai thc d liu lu tr trn my tnh.

Mt c s d liu kiu quan h khng cn phi lu tr cc d liu c lin quan vi nhau nhiu ln trong cc bng d liu khc nhau.

1.1.2 Khi ng v thot khi ACCESS

Khi ng Access: Dng Start Menu/ShortCut hay dng lnh RUN (tp khi ng ca Access l MSACCESS.EXE).

Kt thc lm vic vI Access Chn menu File Exit hay click nt Close hay dng phm tt ALT+F4

1.1.3 TaskPane

Mc nh, khi khi ng Access 2003, TaskPane hin th cnh phi mn hnh.

Tt m TaskPane : Ctrl+F1 hoc chn menu View TaskPane

1.2 KHI NIM V TP TIN C S D LIU

- Gii thiu v Access 2003 - Khi nim v c s d liu - Xc lp mi trng lm vic

Microsoft Access

2

1.2.1 Tp tin C s D liu

ACCESS lm vic vi tp tin CSDL (Datebase) c phn m rng l .mdb v c th khi nim nh tp hp cc thng tin ln quan n mt ch th lm vic v c ghi lu trong mt tp tin theo nh dng ca ACCESS.

1.2.2 M tp tin C s D liu

M tp tin CSDL t TaskPane To tp tin t CSDL mi

o Click mc Create a new file m New File TaskPane

o Chn cch to tp tin CSDL mi - Blank Database: tp

CSDL rng - Blank Data access page : Trang d liu Access rng - From existing file : To tp CSDL mi bng cch sao

chp tp CSDL c trn Disk - Project : n Access (loi File mi ca Access .adp

dng lm vic vi SQL Server Database)

M tp tin CSDL c sn (Open an Existing Database): o Chn tn tp CSDL cn m trn phn OPEN (nu c hin

th) o Hay click More : m hp thoi Open v chn tp CSDL

cn m

M tp tin CSDL t Menubar Chn Menu FILE - NEW / OPEN (phm tt : Ctrl+N /

Ctrl+O) v tip tc cc bc tng t nh nu trn.

GHI CH Cc tp tin CSDL c thit k vi ACCESS 2000 tr ln mi c th m vi ACCESS 2003. Nu m tp CSDL thit k vi ACCESS 97 trong ACCESS 2003, cn phi convert sang ca ACCESS 2000 hay ACCESS 2002-2003.

1.2.3 Cc i tng ca CSDL ACCESS lm vic vi tp tin CSDL (.MDB) v gm 7 loi

i tng

Microsoft Access

3

TABLES: (Bng D Liu) Loi i tng c bn v quan trng nht ca CSDL dng thit k cc d liu c s, ghi cc bin ng cn qun l, khai thc.

QUERIES: (Bng Truy Vn) Cng c truy vn thng tin v thc hin cc thao tc trn d liu ca TABLE . Query c dng lm nn tng lm cc bo biu c c tnh nh dng cao hn Table.

FORMS: (Biu Mu) Dng thit k mn hnh nhp liu mt cch sinh ng hoc iu khin hot ng ca chng trnh ng dng.

REPORTS: (Bo Biu) L kt qu u ra ca qu trnh khai thc d liu c ngun gc t cc Table hay Query.

PAGES: (Trang) cc trang d liu Access thit k theo dng Web.

MACROS: (Tp Lnh) Cng c ca Access gip to cc hnh ng n gin khi xy dng ng dng m khng cn dng ngn ng lp trnh.

MODULES: (n Th) Dng vit cc dng lnh cho ng dng theo ngn ng Visual Basic. y l cng c lp trnh chuyn nghip ca Access.

1.2.4 Ca s DATABASE

Khi mt CSDL c m, ca s Database ca CSDL (cn gi l Database Container hay Database Window) c hin th v gm

Toolbar

Khung ni dung

Khung i cng

Microsoft Access

4

Thanh tiu Gm bn tri l DATABASE (Kiu nh dng) v bn phi l cc nt iu khin ca s (phng to, thu nh, ng ca s).

Thanh dng c L thanh dng c ca Ca s Database : Hiu lc vi cc mc chn trong ca s ny v thng gm Open (m trong ch lm vic), Design (M trong ch thit k), New (m mi), Close (ng ca s Database), cc Icon chuyn i ch hin th trong khung ni dung.

Khung i cng gm nt Objects, Groups v biu tng Favorites - Objects: Dng m hay thu gn danh mc cc loi i

tng ca Database - Groups : Dng m hay thu gn danh mc lm vic vi

nhm - Favorites: M danh mc cc i tng trong th mc

Favorites. Khung ni dung

- Pha trn l cc shortcut to mi i tng thuc loi i tng c chn trong khung i cng.

- Pha di l danh mc cc i tng thuc loi c chn bn khung i cng.

ng ca s CSDL l ng tp CSDL ang m. 1.3 XC LP MI TRNG LM VIC

1.3.1 Xc lp mi trng h thng

Xc lp mi trng h thng nh dngthc hin v ngy thng, d liu kiu s (dng chung trong mi trng Windows).

M hp thoi REGIONAL AND LANGUAGE OPTIONS Xc lp khu vc (Regional Options) Mc nh khu vc c xc lp l English (United States).

Nu chn mc FRENCH (Standard) th cc xc lp v hin th s v ngy ph hp vi dng thc thng dng ti Vit Nam.

Nu chn xc lp khu vc l English (United States) v mun hin th dng thc d liu s v ngy theo quy c c dng ti nc ta th phi xc lp li phn nh dng s, nh dng tin t v nh dng ngy.

1.3.2 Xc lp mi trng ACCESS

Microsoft Access

5

M hp thoi xc lp : chn Menubar TOOLS - OPTIONS - thc hin xc lp.

Cc Phiu ca hp thoi gm View: Hin th thanh tnh trng, hp thoi khi ng, v.v. General: nh l trang, th mc lm vic mc nh . Edit/Find: Chn cch tm kim, xc nh khi thay i

Record Action queries hay xa i tng CSDL. Keyboard: X l di chuyn cursor khi dng phm ENTER,

mi tn. DataSheet: nh dng cho DATASHEET (Font, hnh dng,

v.v.) Forms/Reports: S dng khung dng, v.v. Advanced: Cc thit lp lin quan n nhiu ngi dng. Tables/Query: Cc thit lp lin quan Bng, Queries Default

size,Type,v.v.) Cc xc lp thng dng Phiu General

- Print Margin: Xc lp l trang in - Use fuor-digit year formatting: Xc lp nh dng 4 k s

nm - Compact on close: Nn khi ng CSDL - Default Database Folder: Th mc mc nh ca CSDL

Phiu DataSheet

- Default Font: Xc lp Font mc nh. - Default color: Mu mc nh cho k t, nn ng li.

Microsoft Access

6

- Default Gridline Showing: Xc lp mc dnh hin th ng li.

- Default Column Width: Xc lp chiu rng mc nh ca ct

- Default Cell Efect: Xc lp dng hin th Phiu Find / Edit

- Default Find / Replace: Xc lp vic tm v thay - Confirm: Xc lp yu cu xc nhn khi xa CSDL, thc

hin vn tin hnh ng, thay i mu tin.

Microsoft Access

7

BI TP: 1. Khi ng Access v quan st mn hnh lm vic ca Access.

Tm hiu cc chc nng ca h thng menu trong Access.

2. To mt tp tin CSDL trong Access, t tn cho tp tin ny l QLHS.MDB

3. ng tp tin QLHS.MDB li. i tn tp tin ny thnh QLSV.MDB

4. To folder BT_Access trn D. To tp tin CSDL mi t tn THUVIEN.MDB trong folder BT_Access.

5. Thit lp mi trng lm vic: Font ch ting Vit, bng m Unicode, kiu g VNI (hoc Telex). Qui nh cch nhp d liu thi gian dng ngy/thng/nm (hin 4 s).

6. Thot khi Access. Chp tp tin QLSV.MDB vo folder BT_Access.

7. Khi ng Access, m li tp tin QLSV.MDB v xem kch thc ca tp tin.

Microsoft Access

8

- Nhng giai on thit k ng dng - To tp tin CSDL - Khi nim v Bng - Thit k cu trc Bng - Nhp liu vo Bng - Cc thuc tnh thng dng - Thit lp Lookup

CHNG 2

TO CSDL V BNG 2.1 NHNG GIAI ON THIT K NG DNG CSDL

Khi thit k mt ng dng CSDL (gm CSDL v cc thao tc khai thc), cn tin hnh cc bc sau:

2.1.1 Xc nh mc ch ca CSDL CSDL dng lm g: xc nh nhng ch th d liu cn

thit (Bng d liu Table) v d liu cn lu tr (cc Field ca mi Bng).

2.1.2 Xc nh cc bng d liu cn thit Xem xt cc thng tin mun ly t CSDL v phn chia thng

tin thnh nhng ch th c bn. Mi ch th c t chc trong Table ring.

2.1.3 To lp cc Table Xc nh vng d liu (Field) ca mi Bng. Mi vng phi c quan h trc tip vi ch th d kin. Nu

mi vng no ca Record li m t mt ch th d liu ca Table khc th vng ny cng c nh ngha trong Table ny lm c s thit lp mi quan h gia cc Table sau ny.

Khng ghi nhng d liu phi tnh ton vo Table. Lu tr cc d kin theo cc thnh phn lun l nh nht.

2.1.4 Thit lp mi quan h gia cc Bng Xem xt s lin quan d liu gia cc Bng v thit lp quan

h trn c s cc Field lm tiu chun quan h. Field lm tiu chun quan h gia cc Bng gi l mc Kha (Key).

2.1.5 Thit k cc cng c khai thc d liu

Microsoft Access

9

Thit k mn hnh xut nhp d liu dng nhp liu, hin th thng tin v kt xut ra my in.

2.1.6 n nh cc thao tc x l cho ngi s dng Thit k cc cng c iu khin hot ng to tin nghi

cho ngi s dng khi thao tc vi ng dng. 2.2 TO C S D LIU

Khi lm vic vi Access, mi vic ch c th bt u khi c mt tp tin c to v c m.

C 2 cch to tp tin CSDL: dng DATABASE WIZARD to Database vi cc thnh phn km theo hoc to mt Database rng ch ng thit k cc thnh phn theo yu cu ring ca ngi s dng.

2.1.1 Dng Database Wizard

M hp thoi Templates Trn TaskPane, chn mc New File hay Ctrl+N Ti phn Templates, click lin kt On Cumputer m

hp thoi Templates. Nu mun dng Templates trn mng th click mc Templat on Office online.

Trn hp thoi Templates Chn phiu Databases Chn ch ri click OK

Thc hin cc bc theo hng dn ca Wizard 2.1.2 To CSDL rng

Microsoft Access

10

C th to CSDL rng t thit k cc i tng Tables, Reports, v.v theo nhu cu ring.

Quy trnh Trn TaskPane, chn mc New File hay Ctrl+N Ti phn New, click lin kt Blank Database Nhp tn tp CSDL trong hp thoi File New Database ri

click nt Create. CSDL mi c to v hin th Ca s Database. Mun thao

tc vi loi i tng no th chn mc loi i tng y khung i cng (khung tri).

GHI CH: Khi to CSDL theo cch ny, ban u khng c Bng d liu no c. Do vy phi to Bng d liu trc ri mi thao tc vi cc i tng khc. 2.3 KHI NIM V BNG (TABLE)

2.3.1 Vai tr ca Bng Bng l i tng c bn v quan trng nht ca CSDL trong

Microsoft Access, dng ghi nhn v khai thc nhng thng tin mun qun l (d liu c s).

2.3.2 Cu trc ca Bng

2.3.2.1 Khi qut Mt Bng c t chc thnh ct (Field) v dng (Record -

tin) Mi ct ng vi mt kiu d liu cn lu tr. Mi dng l mt tin (Record), l tp hp cc Field v chc

thng tin lin quan n i tng c th. To Bng: thit k cu trc trc v sau , nhp cc tin. Thit k cu trc cho Bng l to phn Header cha tn cc

Field v gn thuc tnh cho mi Field. 2.3.2.2 Tn Field Di ti a 64 k t k c v gm k t ch ci, k t s, k t

trng, cc k t c bit t tn cho Field. Khng c dng du chm (.), du chm than (!) v du ngoc vung([])

Khng th bt u bng k t trng Tn Field phi duy nht (khng trng nhau) v khng trng

vi tn hm, t kha ca Access.

Microsoft Access

11

Access cho php dng k t trng v k t c bit t tn Field nhng khng khuyn khch s dng cc k t ny tin li khi dng biu thc v lp trnh.

2.3.2.3 Kiu d liu ca Field Chn kiu d liu Mc nhin, Access gn kiu Text cho Field to mi. Hy

xc lp kiu d liu cho Field bng cch chn kiu d liu trong hp danh sch xung ct Data Type trong mn hnh Design View. Khi xc lp kiu cho Field, cn ch nh loi d liu (Text,

s, v.v), kch thc dnh cho Field (Field Size), ch mc v cc xc lp khc (ty thuc vo kiu d liu ca Field)

Cc kiu d liu Text (vn bn)

Cha vn bn gm k t ch ci, s, khong trng v cc k t khc. Di ti a 255 k t (mi byte mt k t). Memo (k c)

Ging nh Field kiu Text nhng c chiu di ti a n 65535 k t. Number (s)

Cha cc gi tr s. Ch cha cc k s t 0 n 9, du phn cch thp phn, du m (-). Chiu di ti a c th l 1,2,4,8,12 bytes. Cc loi gi tr lu trong Field ny thng dng l - Byte: Gm cc gi tr nguyn (khng c phn thp phn)

t tr 0 n 255 v chim 1 byte. - Integer: Gm cc gi tr nguyn (khng c phn thp

phn) t tr -32,768 n 32,767 v chim 2 bytes. - Long Integer: Gm cc gi tr nguyn (khng c phn

thp phn) t tr -2,147,843,648 n 2,147,843,647 v chim 4 bytes. Cn gi l s nguyn di.

- Single: Gm cc gi tr t -3.4E38 n 3.4E38 v chim 4 bytes. Cn gi l s tinh xc n (tinh xc 7 ch s thp phn).

- Double: Gm cc gi tr t -1.79E308 n 1.79E308 v chim 8 bytes. Cn gi l s tinh xc kp (tinh xc 15 ch s thp phn)

Currency (tin t) Gm cc gi tr t -922,337,203,685,477.5808 n 922,337,203,685,477.5807 v chim 8 bytes. (Tinh xc n 15 ch s phn nguyn v 4 ch s thp phn)

Microsoft Access

12

Date/Time (ngy/gi) Cha tr thi gian t nm 100 n nm 9999, chim 8 bytes. AutoNumber (s in t ng)

Gm cc gi tr kiu s v Access t ng gn cho mi Record mt tr tng ng (khi u l 1,2, v tng dn). Tr m ny c tip tc tng v khng trng lp ngay c vi cc tr ca Record c xa. Kch thc 4 bytes. Yes/No

Cha cc tr Logic v ch nhn hai gi tr l Yes/No. Chiu di l 1 bit. OLE Object

Cha cc i tng do cc ng dng khc trong Windows cung cp h tr lin kt (Object Linking) v nhng (Embedding). Dng kiu ny lu hnh nh, m thanh bng tnh hay vn bn (to bi trnh x l khc). C th cha n 1 GB. Hyperlink

Cha cc siu lin kt. Lookup Wizard y khng phi l thuc tnh ng ngha, ch dng thit k mt danh sch chn cho Field ch nh theo hng dn ca Wizard.

2.3.3 Cc mc kha (key)

2.3.3.1 Cng dng ca Mc kha Mt hay nhiu Field c ch nh lm mc kha nhn

din cc mu tin ca mt Bng hay dng thit lp mi quan h gia cc Table. Access phn bit hai loi mc kha : kha chnh v kha

ngoi. 2.3.3.2 Mc kha chnh (Primary Key) L mc kha thit lp trn mt hay nhiu Field nhn din

duy nht cc mu tin ca mt Bng v c th dng lp mi quan h vi cc Bng khc. Tr ca Field mc kha chnh duy nht v khng l tr

NULL Nn to Field mc kha chnh vi chiu di nh nht c th c v c nh hng tc truy xut.

2.3.3.3 Mc kha ngoi (Foreign Key)

Microsoft Access

13

L mc kha thit lp trn mt hay nhiu Field ca Bng v dng tham chiu n mt hay nhiu Field l kha chnh trong Table khc. Mt Foreign Key ch ra mi quan h ca Bng ny vi cc

Bng cha kha chnh tng ng. Kiu d liu trong Field c ch nh l Foreign Key v

Primary Key phi cng kiu v chiu di vi nhau (khng nht thit cng tn).

2.3.4 Ch lm vic vi Bng

C hai ch lm vic vi Bng Vi Datasheet view (ch bng biu): nhp, xa, hiu

chnh Record. Vi Datasheet Design (ch thit k): thit lp hay hiu

chnh cu trc Bng. 2.4 THIT K CU TRC BNG

2.4.1 Cc cch thc hin

T ca s Database - chn mc Tables trong khung i cng v thc hin mt trong cc thao tc sau.

Click mc New trn Toolbar ca ca s Database, hp thoi New Tables c hin th - Chn mt trong cc mc sau.

Database View: To Bng theo ch Datasheet View (t nhp d liu) Design View:

To Bng theo ch t thit k. Table Wizard:

To Bng theo hng dn ca Wizard. Import Table:

Du nhp Bng t mt CSDL khc. Link Table: Ni kt Bng.

Hoc click shortcut lin quan trong khung ni dung Create Table in Design View: To Bng trong khung Design

View

Microsoft Access

14

Create Table by using Wizard: To Bng vi Table Wizard Create Table by entering Data: To Bng bng cch nhp trc

tip. 2.4.2 To Bng bng Wizard

Chn mc Table Wizard t hp thoi New Table v thc hin cc bc ca Wizard hay shortcut Create Table by using Wizard.

Bc 1: Chn loi Bng, Bng mu v Field mu Chn loi Bng (Table Categories): Business hay Personal. Chn Bng mu trong khung Sample Tables. Chn cc Field trong Sample Fields chuyn sang khung

Fields in my new table (Double click hay cc nt du >, >>,

Microsoft Access

15

o Number I enter when I add new records: ngi s dng t in tr cho Field v l tr s kiu.

o Number and/or letters I enter when I add new records: ngi s dng t in tr cho Field v l tr kiu s hay k t.

o Khai bo xong, click Next qua bc k tip.

Bc 3: To mi quan h gia Bng mi vi cc Bng hin c

ca CSDL

Microsoft Access

16

Nu Bng ang to l Bng u tin ca CSDL th Access b qua bc ny.

Ngc li nu CSDL c Bng th Access phng on rng Bng mi c th c quan h n cc Bng hin hnh v hin th bc ny. Nu mun to cc mi quan h gia Bng mi to vi cc Bng c th chn tn Bng cn khai bo quan h vi Bng ang to ri click vo nt RELATIONSHIPS trn hp thoi khai bo quan h.

Bc 4: Kt thc, chn mt trong cc mc sau

Modify the Table design (hiu chnh cu trc) Enter DATA directly into the Table (nhp trc tip DATA) Enter DATA into the Table using a form the Wizard creates

for me (Nhp DATA qua FORM) Mc Display Help on working with the Table: hin th Help

khi lm vic vi Bng Click FINISH kt thc giai on thit k. Tip theo hp

thoi ca Bng va to s hin ra nhp liu (theo hnh thc trc tip hay di hnh thc ca mt Biu mu).

2.4.3 To Bng bng cch nhp trc tip d liu (dng Datasheet View) Chn mc

Datasheet View t hp thoi New Table hay chn shortcut Create new Table by entering data.

Microsoft Access

17

Mt Bng hin ra vi 10 ct 22 dng. Cc ct c tn l Field 1, Field 2, . Field 10.

Nhp trc tip d liu vo Bng. i tn Field Click phi tn ct - chn Rename Column trn Shortcut

Menu. Hay ng vo mt bt k trn ct mun i tn v chn

menu Format - Rename Column. Xa cc ct: chn ct mun xa v chn Delete trn shortcut

Menu hay chn menu Edit Delete Column. Thm ct: chn ct ni mun thm ct mi v chn Insert

Column trn shortcut Menu hay chn menu Insert Column. Thit k xong, ng Bng: Access s yu cu t tn cho Bng

mi (v xc nh Primary Key nu cha c) v cc ct tha s t ng c xa.

2.4.4 T thit k Bng bng Design View Chn mc Design View t hp thoi New Table hay chn

shortcut Create new Table in Design View. Mn hnh Table Design View gm 2 phn:

2.4.4.1 Phn thit k cu trc Bng Gm ct Field Name, Data Type v Description. Field Name (Tn Field): ti a 64 k t v bt u bng k t

ch ci hay s. Data Type (Kiu d liu): chn kiu d liu trong danh sch

( nu mc trn)

Phn thit k

Phn thuc tnh

Microsoft Access

18

Description (Din gii): ty chn. Dng ghi cc ch thch lin quan n Field.

2.4.4.2 Phn thuc tnh Gm phiu General v Lookup. Phiu General quy nh cc thuc tnh Field. Phiu Lookup to danh sch chn cho Field.

Nhn phm F6 chuyn i qua li gia phn thit k cu trc v khai bo thuc tnh.

2.4.4.3 Xc lp Primary Key Vic xc lp Primary Key tuy khng bt buc nhng nn thc

hin. Nu kt thc thit k Bng m khng xc lp Primary Key th

Access s thc hin thng bo nhc nh

- Chn Yes lp Primary Key - Chn No khng to Primary Key - Chn Cancel tr li mn hnh thit k v khng to

Primary Key. Ch c xc lp mt Primary Key trong mt Bng. Cch xc

lp: Chn Field mun xc lp

- Xc lp Primary Key cho mt Field: chn hay ng ti Field mun xc lp Primary Key.

- Xc lp cho Primary Key gm nhiu Field: phi hp vi phm Shift hay Ctrl chn cc Field mun xc lp lm Primary Key.

Click biu tng cha kha trn Toolbar Hay t menu EDIT - Primary Key Hay click phi v chn Primary Key trn shortcut Menu.

2.4.4.4 Ghi lu Thit k xong, ghi lu Bng v ng hp thoi thit k. Nu

cha ghi lu, Access s nhc ghi lu Bng.

Microsoft Access

19

2.5 NHP LIU VO BNG 2.5.1 Khi qut

C th nhp, hiu chnh d liu trong Bng theo nhiu cch: Nhp, hiu chnh trc tip khi lm vic vi Bng. Hoc khi lm vic vi Querys Datasheet. Hoc khi lm vic vi biu mu.

2.5.2 Trc tip nhp d liu vo Bng M Bng cn nhp liu

T Database Window, chn mc loi Tables bn khung i cng v chn tn Bng cn nhp liu ri click Open trn Menu ca hp thoi ny.

Hay double click ln tn Bng. Bng c hin th dng Datasheet View.

2.5.2.1 Cch nhp Vi cc Field thng

- Nhp, hiu chnh bnh thng. Nhp record mi vo dng trng k tip tin cui.

- Hoc chn Menu RECORD DATA ENTRY. Trn Bng ch hin th Record trng nhp liu.

- Mun hin th li cc Record ca Bng: chn menu RECORD REMOVE FILTER/SORT

Vi Field kiu AutoNumber: Access s t nhp. Vi Field kiu OLE Object

- ng ti Field ca record mun a 1 Object vo: chn menu Insert Object (chn Create New hay From File)

- Hay Copy vo Clipboard hnh nh ri Paste vo Field OLE. - Hiu chnh mt Object: ng trong Field c Object mun

hiu chnh v double click, ng dng lin quan c m hiu chnh.

2.5.2.2 Record Selector: biu th trng thi ca tin. Nu C hnh tam gic: tin hin hnh. C hnh cy bt: tin ang c hiu chnh hay nhp liu. C hnh hoa th: tin trng lin k tin cui cng.

Microsoft Access

20

2.5.2.3 Cc phm tt thng dng

Phm tt ngha Tab/Shift+Tab n Field k tip / Field trc Home/End n Field u / cui ca Record hin hnh. Ctrl+PgUp/PgDn n Record trc / sau (khi dng Biu mu) Ctrl+Home/End n Field u ca Record u/ Field cui ca

Record cui Shift+F2 Zoom Field c cha d liu Text ln hay

Memo F2 Chuyn sang ch lm vic vi Field

2.6 CC THUC TNH S DNG 2.6.1 Khi qut Property (thuc tnh) l cc tnh cht gn cho mi i tng lin

quan. Cc tnh cht ny c th do Access t gn khi i tng c to hay do ngi s dng gn cho i tng. Thuc tnh ca Field l cc tnh cht lin quan n Field. Thuc tnh ca Bng l cc tnh cht lin quan n Bng.

Property Sheet hay Property Window (Ca s thuc tnh) dng thao tc vi cc thuc tnh ca i tng.

M ca s thuc tnh: click biu tng Properties trn Toolbar hay chn menu VIEW Properties m ca s thuc tnh ca Bng.

Thao tc vi thuc tnh ca Field: Khai bo trong phn Properties ca ca s thit k Bng (Design View).

2.6.2 Cc thuc tnh thng dng 2.6.2.1 Thuc tnh Caption

L biu thc chui di ti a 2.048 k t. i vi Form v Report, nu Caption di hn Tittle Bar th s b ct bt. Cng dng:

Caption ca Field Tiu ct cho Field (Datasheet ca Table/Query) Caption ca Form / Report Lm tiu cho Form / Report Caption ca Control v Label Text xut hin trong Control, Label.

2.6.2.2 Thuc tnh FieldSize c dng nh kch thc ti a cho mt Field. Cn ch

nh Fieldsize va vi yu cu d liu c tc x l nhanh v tit kim vng nh. 2.6.2.3 Thuc tnh Format

Dng n nh dng hin th ca d liu. Thuc tnh ny s dng cc xc lp khc nhau cho nhng kiu d liu khc nhau.

Microsoft Access

21

K t nh dng dng chung Dng k hiu sau xy dng bt k nh dng kiu d liu no

K hiu M t (Space) Hin th khong trng nh cc k t ABC Hin th bt c g trong ngoc kp nh cc k t ! Bt buc canh tri thay v canh phi * in cc khong trng kh dng vi cc k t k tip \ Hin th k t k tip nh k t bnh thng [Color] Mu (Black, Blue, Green, Red, Cyan, Magenta,

Yellow, White).

Custom Format dng ring cho Text v Memo Cc phn ca nh dng

Phn M t Phn th 1 nh dng cho Field vi vn bn Phn th 2 nh dng cho tr NULL hay chui rng 2 phn cch nhau bi du chm phy. V d: @;None

Cc k hiu nh dng K hiu M t

@ Bt buc l khong trng hay mt k t & Khng bt buc l khong trng hay mt k t < i tt c k t thnh ch thng > i tt c k t thnh ch hoa Custom Format dng ring cho Logical Data

Cc phn ca nh dng Phn M t

Phn th 1 Phn ny khng tc dnh nhng phi g du chm phy gi ch.

Phn th 2 Vn bn hin th thay cho tr True, Yes, On. Phn th 3 Vn bn hin th thay cho tr False, No, Off.

V d: ;Always [Blue]; Never[Red] Lu : xc lp nh dng c hiu lc: chn mc TextBox ca phiu

Lookup (phn Properties ca ca s thit k). Custom Format dng ring chu Number

Cc phn ca nh dng Phn M t

Phn th 1 nh dng s dng Phn th 2 nh dng s m Phn th 3 nh dng s zero Phn th 4 nh dng cc tr NULL

Microsoft Access

22

Cc k t nh dng K hiu M t

. (chm) , (phy)

Du phn cch thp phn v phn cch hng ngn (xc lp trong Control Panel)

0 K s gi v tr. Hin th k s hay s 0 # K s gi v tr. Hin th k s hay khng c g c $ Hin th k t $ % Phn trm. Gi tr c nhn 100 v k hiu % ni vo E- hay e- E+ hay e+

K hiu khoa hc

2.6.2.4 Thuc tnh Input Mask Dng nh dng d liu nhp. Thuc tnh ny s dng cc

xc lp khc nhau cho nhng kiu d liu khc nhau. Cc phn ca nh dng Phn M t

Phn th 1 Ch nh Input Mask cho field (V d: !(999)999-9999) Phn th 2 C 2 tr: nu l 0, ghi d liu v c cc k t nh dng.

Nu l 1 hay trng, ch nhng d liu nhp vo mi c ghi vo Bng.

Phn th 3 Ch nh k t hin th thay cho khong trng (c th dng dng bt c k t no hay chui rng )

Cc k hiu dng trong Input Mask K hiu M t 0 K t s (0-9) v bt buc. Khng c dng du cng

tr (+,-) 9 K t s hay khong trng (khng bt buc), khng cho

php du cng tr. # K t s hay khong trng, cho dng du +,- (mc khng

bt buc) L K t ch (A-Z) v bt buc. ? K t ch (A-Z) v khng bt buc. A Mu t hay k s (mc bt buc). a Mu t hay k s (mc ty ) & K t bt k hay khong trng (mc bt buc). C K t bt k hay khong trng (mc ty ). . , : ; - / Du phn cch thp phn, hng ngn, ngy gi (theo

Control Panel) < Chuyn tt c thnh ch thng.

Microsoft Access

23

> Chuyn tt c thnh ch hoa. ! Canh tri. C th km k t ny vi bt k Input Mask

no. \ K t theo sau hin th nh mt k t bnh thng. (V

d: \A s c hin th ng l A).

GHI CH: t thuc tnh Input Mask l t Password s to ra mt Control bo mt d liu nhp vo (k t nhp vo c lu bnh thng nhng hin th thnh du hoa th(*))

Vi kiu Input Mask thng dng Input Mask V d

(000) 000-0000 (206) 555-0248 (999) 999-9999 (206) 555-0248 hay ( ) 555-0248 (000) AAA-AAAA (206) 555-TELE #999 -20 >L????L?000L0 GREENGR339M3 hay MAY R 452B7 >L0L 0L0 T2F 8M4 00000-9999 98115- hay 98115-3007 >L

Microsoft Access

24

Dng hai thuc tnh Required v ZeroLength phn bit gia thng tin cha tn ti (lu nh chui

rng) v thng tin tn ti nhng cha bit (tr Null). V d: phn bit khch hng c in thoi nhng cha bit s v khng c in thoi.

Nu t AllowZeroLength l Yes: cho php nhp chui rng vo Field bt chp xc lp thuc tnh Required.

Nu t Required l Yes v AllowZeroLength l No: khng cho php nhp chui rng vo Field.

C th dng Input Mask khi nhp liu vo Field phn bit cch hin th tr Null v chui rng (V d: dng None khi nhp chui rng)

lm c hiu lc mt mi quan h gia cc Bng quan h m ta khng cho php tr Null - t thuc tnh Required ca Foreign Key Field ca Bng

quan h l Yes. - Nu Foreign Key l mt phn ca Primary Key ca Bng con

th iu ny khng cn cn thit v Primary Key khng chp nhn tr Null.

Kt qu khi phi hp 2 thuc tnh Required v AllowZeroLength Required AllowZeroLength Thao tc Tr ghi lu No No Nhn Enter, Spacebar

Nhp 1 chui rng Null Khng cho php

No Yes Nhn Enter, Spacebar Nhp 1 chui rng

Null Chui rng

Yes No Nhn Enter, Spacebar Nhp 1 chui rng

Khng cho php Khng cho php

Yes Yes Nhn Enter Nhn Spacebar Nhp 1 chui rng

Khng cho php Chui rng Chui rng

2.6.2.7 Thuc tnh Validation Rule Validation Text Validation Rule

Quy tc kim tra hp l d liu nhp vo. Quy tc c xc lp l biu thc bt k v di ti a 2.048 k t.

Phn bit ValidationRule cp Field v cp mu tin Validation Rule cp Field quy nh quy tc nhp liu vo

Field . - Thit lp biu thc iu kin trong Properties ca Field - Biu thc iu kin khng tham chiu n Field khc - c thi hnh khi kt thc nhp liu mt Field

Microsoft Access

25

Validation Rule cp mu tin quy nh quy tc nhp liu cho ton mu tin (y l thuc tnh ca Bng) - Thit lp biu thc iu kin trong Properties ca Bng

(click phi vo vng trng ca Bng thit k v chn Properties).

- Biu thc iu kin c th tham chiu n Field khc. - ValidationRule c thi hnh khi kt thc nhp 1 tin.

Quy nh thuc tnh ValidationRule L biu thc iu kin, c th cha ccphp ton so snh, lun

l nh < > = (so snh), And Or Not (lun l), Like (chui) Nhn Shift+F2 m rng khung ValidationRule (ca s

Zoom) hay click nt 3 chm m hp thoi Expression Builder v thit lp cc biu thc. i vi quy tc d liu ca Field v Record

Biu thc khng th cha User Defined Function, Aggregate Function, cc tham chiu.

Validation Text Chui k t thng bo khi d liu nhp khng ng vi quy

tc kim tra. Chui k t di ti a 255 k t. Vi v d

0 Tr nhp vo phi khc khng >1000 Or Is Null Tr nhp vo phi ln hn 100 hay rng Like A???? Tr nhp vo phi c 5 k t v bt u l ch A >= #1/1/96#And

Microsoft Access

26

Trong dng trng u tin ca Index Name: nhp tn cho Index Trong ct Field Name, click chn Field u tin cho Index t

trong danh sch xung (DropDown List). Trong dng k tip ca ct Field Name, chn Field th 2 cho

Index (b trng ct Index Name ca dng ny). Lp li bc ny cho n khi chn tt c cc Field mun bao gm trong Index ny. C th dng ti a 10 Field ca Index Field phi hp.

Nu Primary Key ca mt Bng l Field n, thuc tnh Index

s c gn cho (No Duplicates). Khng th t Index cho Field c kiu l Hyperlink, Memo

hay OLE Object. 2.7 THIT LP LOOKUP

2.7.1 Gii thiu C th quy nh d liu nhp ca mt Field phi l mt trong

cc tr nh trc. Danh sch cc tr nh trc c th c to trc tip hay trch

t mt Bng hay Query khc. tin li cho ngi dng, c th khai bo danh sch cc tr

nh trc v ngi dng ch cn chn tr thch hp y chnh l to Lookup cho Field.

Cch thit lp Lookup Dng Lookup Wizard Hay khai bo trc tip trong phn Properties ca Field

2.7.2 To Lookup vi Lookup Wizard 2.7.2.1 Quy trnh

Trong ct Data Type, xc lp kiu cho Field trc ri chn mc Lookup Wizard cng trong danh sch tri xung trong ct Data

Microsoft Access

27

Type khi ng Lookup Wizard v thc hin cc bc theo hng dn. 2.7.2.2 Cc bc ca Lookup Wizard Chn cch khai bo danh sch tr nh trc

Gm chn tr t Bng/Truy vn hoc t nhp danh sch tr.

Khai bo danh sch tr Nu chn cch t nhp danh sch tr, mn hnh nh sau

- Nhp s ct ca Danh sch - Nhp tr vo tng ct ca Danh sch (mi dng l 1 mc

chn) - Click Next: chn ct cha tr nhp vo Field nu mc

c chn

- Click Next: t nhn cho Lookup, click Finish kt thc.

Nhp s ct ca Danh sch

Nhp ni dung vo cc ct

Microsoft Access

28

- Kt qu nh sau

Nu chn ly danh sch tr t Bng hay Truy vn th mn hnh

nh sau

- Chn loi i tng ngun cn hin th (Bng hay Truy

vn hay c hai) v chn tn i tng ngun - Click Next qua bc k tip: chn Field hin th trong

Lookup

- Click Next qua bc k tip: khai bo xp th t mu tin

Microsoft Access

29

- Click Next qua bc k tip: khai bo b rng ct danh

sch

- Nu nh du chn mc Hide key Column th ct kha s

c n khi hin th danh sch. - Click qua bc k tip: chn Field ca danh sch cha

tr nhp vo Field khi mt mc c chn.

- Click Next qua bc k tip: t nhn cho Lookup v

click Finish kt thc. 2.7.3 T thit k Lookup

Microsoft Access

30

Trong ca s thit k Bng, ng ti tn Field ( khai bo Field Type) cn to Lookup.

Chn phiu Lookup trn phn Properties v khai bo

Mc Gi tr ngha Display Control

Combo Box, List Box, Check Box hay Text Box

Dnh hin th l Combo Box, List Box, Text Box hay Check Box. Chn Combo Box

Row Source Type

Table/Query hay Value List

Ngun cung cp d liu cho Lookup Table/Query: ngun l Bng hay

Query Value List: ngun l tr quy nh

trc tip. Row Source SELECT hay

(danh mc quy nh)

Ngun d liu (Lnh SQL hay tn Bng/Query) hoc tr nhp trc tip Nu l tr nhp trc tip th nhp tr theo tng dng v cnh nhau bi du chm phy

Bound Column

Mt s nguyn dng

Ch ct ca danh sch rng buc vi Field

Column Count

Mt s nguyn dng

S ct ca Combo Box hay List Box

Column heads

Yes/No C Tiu ct hay khng

Column Widths

n1; n2 rng ca cc ct (nu 0: khng hin th ct) phn cch bi du chm phy.

List Row Mt s dng S dng ca danh sch List Width Mt s dng Chiu rng danh sch (tnh chung

cc ct) Limit to List Yes/No Cho php (Yes)/ khng cho php

(No) nhp vo Field ca Bng mt tr ngoi danh sch ca Lookup.

V d mt mu khai bo

Microsoft Access

31

- Loi ngun d liu l Table / Query - Ngun d liu l Bng LOP - Ct rng buc l ct 1 ca Bng LOP - Danh sch c 2 ct - Hin th danh sch vi 3 dng - Khng cho php nhp ngoi danh sch ca Lookup

Microsoft Access

32

BI TP: 1. To tp tin CSDL qun l cc cng trnh xy dng, t tn

QLCT.MDB 2. Trong tp tin QLCT.MDB hy to cc table sau y:

Table CONGTRINH c cu trc sau: t kha chnh l MACT

Field Name Data Type Field size Yu cu MACT Text 5 M cng trnh, kha chnh.

Gm 2 k t CT v 3 k s (ch CT c lu trong field). Input Mask: CT000;0

TENCT Text 50 Tn cng trnh NGAYKC Datetime Ngy khi cng, nh hn

ngy hin ti Validation Rule: < Date() Validation Text: Ngy khi cng phi nh hn ngy hin ti

Table VATTU c cu trc: t kha chnh l MAVT

Field Name

Data Type

Field size

Yu cu

MAVT Text 5 M vt t, kha chnh. Gm 2 k t hoa v 3 k s. Input Mask: >LL000

TENVT Text 20 Tn vt t , nhp 1 ch u hoa, cn li l ch thng. Input Mask: >L

Microsoft Access

33

NGAY Datetime Ngy xut nh hn hay bng ngy hin ti. Validation Rule: 0

DONGIA Number Long Integer

n gi, nh dng nhm 3 s li c k hiu tin VN v phi nhp ln hn 0 Format: #,### Validation Rule: > 0

3. Lin kt cc Table v nhp d liu sau

Microsoft Access

34

Table VATTU

MAVT TENVT DVT CA001 Ct m3 DA002 xanh tn SA003 St cun kg TL004 Tn lnh mt XM005 Xi mng bao

Table CONGTRINH

MACT TENCT NGAYKCCT001 Nh ngh cng on 01/10/05 CT002 Nh tr Hoa mai 16/12/05 CT003 Cng vin Thng 8 22/01/06 CT004 Nh my Thng li 01/02/06 CT005 Trng Kim ng 10/02/06

Table XUAT_VT

SOPHIEU NGAY MACT X001 01/11/05 CT001 X002 05/12/05 CT001 X003 06/02/06 CT001 X004 21/12/05 CT003 X005 02/03/06 CT003 X006 22/03/06 CT004

Table CHITIET_XUAT

SOPHIEU MAVT SOLUONG DONGIA X001 CA001 12 12000X001 DA002 7 314000X001 SA003 400 4500X002 SA003 100 5300X002 XM005 100 43000X003 CA001 70 15000X003 SA003 120 4000X004 TL004 750 78000X004 XM005 150 45000X005 DA002 9 270000X006 XM005 90 45000X006 CA001 20 18000

Microsoft Access

35

CHNG 3

THAO TC TRN BNG

3.1 HIU NH BNG

Hiu nh mt Bng thay i cu trc Bng, hoc thay i ni dung cc Record hoc thay i cch trnh by.

3.1.1 Thay i cu trc

3.1.1.1 Thay i thuc tnh, thm bt Field M CSDL lin quan, chn v m Bng cn hiu chnh trong

ch thit k (DESIGN VIEW) Thay i thuc tnh:

Chn Field v hiu chnh trong Property Sheet. Nu Field ang gi vai tr quan h (Relation Field) vi mt Bng khc th c th khng hiu chnh c. B Field c:

Chn Field v chn menu EDIT (hay Shortcut Menu) chn DELETE ROW Thm Field mi:

Chn dng ti v tr mun thm vo Field mi v chn menu INSERT ROW hay Shortcut Menu INSERT ROW Sa i cu trc:

Chn dng lin quan Hiu chnh cu trc (ch thc hin hiu chnh khi tht cn thit trnh b mt d liu).

3.1.1.2 Nu ch thay i tn Field M Bng ch DataSheet chn ct lin quan Chn menu Format Rename column hay Menu shortcut Rename column

3.1.2 Hiu chnh tin Sa ni dung Record:

Chn Record lin quan v sa cha ty . Khng th hiu chnh AutoNumber.

Hy b Record:

- Hiu nh Bng - Khai thc thng tin ca Bng

Microsoft Access

36

Chn tin, chn menu EDIT (hay Shortcut Menu) DELETE RECORD hay nhn phm DELETE

Thm Record mi: Nhp vo dng cui cng hay chn menu Insert New Record (cc Record s c sp xp li khi Bng c m ln sau).

Chn ton b cc Record: Nhn Ctrl + A hay chn menu EDIT Select ALL

Sao chp, ct, dn Record: Chn Record dng menu EDIT hay cc t hp phm tt (Ctrl+C, Ctrl+X, Ctrl+V)

3.1.3 Thay i cch trnh by 3.1.3.1 nh dng

M Bng trong ch DataSheet chn menu FORMAT - chn lnh lin quan Mc DataSheet

- CELL EFFECT: Trnh by cc s liu theo dng phng (Flat), nh ln (Raised) hay lm xung (Sunken).

- GRIDLINES SHOW: Hin th ng li ngang dc hay khng (ch hiu lc khi Cell Effect l Flat)

- BACKGROUND COLOR: Xc lp mu nn. - GRIDLINE COLOR: Xc lp mu ng li. - BORDERS AND LINE STYLES: Xc lp kiu ng vin

v ng li. Mc FONT: Thit lp Font ch cho Bng. Mc ROW HIEGHT v mc COLUMN WIDTH n nh cao ca dng v rng ca ct ch nh (c th dng Mouse hiu chnh) Mc RENAME COLUMN

Dng dt tn li cho ct Mc HIDE COLUMN v UNHIDE COLUMN

Che / hin th li ct ch nh Mc FREEZE COLUMN v UNFREEZE COLUMNS

C nh / b c nh ct ch nh. Ct c c nh phi t pha tri Bng.

3.1.3.2 Di chuyn ct Chn ct v nhn gi nt tri Mouse (c hnh ch nht) r n

v tr mi. Khi r, c vt ng xc nh v tr ct 3.1.3.3 Sao chp

Microsoft Access

37

Thao tc Copy vPaste / Paste Special cng tng t nh cc ng dng khc ca b Office. Ngoi ra cn c chc nng Paste Append dng dn ni ui

t Clipboard vo Record hin hnh. Thao tc : chn menu EDIT PASTE APPEND.

3.2 KHAI THC THNG TIN CA BNG 3.2.1 Tm thay

t im nhy vo trong ct cn tm thay. Chn menu EDIT FIND hay REPLACE (phm tt

Ctrl+F/Ctrl+) Nhp ni dung cn tm/thay vo khung Find What (v khung

Replace With). Ch nh cc mc chn

- Match Case: Chnh xc vi mu chn (phn bit ch thng ch hoa)

- Match Wole Field: Mu chn phi chnh xc ton Field - Search Only Current Field: Ch tm trong Field hin hnh - Search Field As Formatted: Tm Field nh nh dng

Click vo mt trong cc nt Ctrl thc hin - Find Next : Tm tip - Replace : Thay th - Replace All : Thay th tt c

3.2.2 Sp xp (SORT)

Sp xp l hin th cc mu tin theo mt trt t no

Sp xp theo tng ct

- ng trong (hoc chn) ct cn sp xp

Microsoft Access

38

- Click nt SORT ASCENDING / DESCENDING trn thanh dng c

- Hay chn menu RECORD - SORT - ASCENDING / DESCENDING

Nu cn sp xp theo nhiu ct - Di chuyn cc ct lin quan n cc v tr cnh nhau (th t

u tin ct kha c tnh t bn tri). - Sau chn cc ct ny ri thc hin SORT tng t nh

nu trn

3.2.3 Lc d liu

Lc l hin th cc mu tin theo mt tiu chun no . Trnh t thc hin: chn menu RECORDS - FILTER - chn mc FILTER thch hp.

3.2.3.1 Filter by Selection Lc theo tr ang c chn no .

- Tiu chun lc l tr ca mt Field ca mt Record: ng trong Field ca Record c tr mun lm tiu chun lc click nt Filter by Selection trn Toolbar hay chn menu RECORD, chn FILTER BY SELECTION.

- Tiu chun lc l mt phn tr ca mt Field ca Record: Chn phn dng lm tiu chun lc ri thc hin lc nh nu trn.

Khng dng c biu thc trong phng thc lc ny. 3.2.3.2 Filter Excluding Selection

Tng t nh Filter by Selection nhng ch nhng Record khng p ng iu kin lc mi c lc. 3.2.3.3 Filter by Form Cch ny c dng t cc iu kin lc cho mt Field c

th. Thit lp iu kin lc

- Click biu tng Filter by Form hoc chn menu RECORD - FILTER - FILTER BY FORM

- Chn Phiu Look For v nhp iu kin lc vo Field lin quan trong hp thoi Filter by Form.

- Chn Phiu OR v nhp b sung iu kin lc vo Field lin quan

Cch nhp iu kin lc y Cch 1 : Khai bo biu thc lc

o iu kin lc l biu thc chui

Microsoft Access

39

Nhp trc tip chui Access s t ng a vo kha Like v t chui trong du nhy kp. C th dng k t i din.

o iu kin lc l biu thc s : nhp bnh thng o iu kin lc l d liu ngy

- Nhp theo quy c Control Panel v t trong du ro (#)

- C th nhp trc tip v Access t ng a vo cp du ro.

o Dng cc tc t - s hc: cng (+), tr (-), nhn (*), chia (/), chia

nguyn (\) - nhm: trong khong (Between And), In (trong) - Logic: And, Or, Not - Tr Null: Is Null, Not Is Null, Is Not Null - so snh: ln / nh hn (>,=,= #05/01/97#

y Cch 2 : Click nt Dropdown Menu chn iu kin lc.

Thc hin lc

Click nt Apply Filter (hnh ci phu) trn Toolbar hay chn menu RECORD - APPLY FILTER / SORT

Microsoft Access

40

3.2.3.4 Advanced Filter / Sort Dng thit lp cc iu kin lc mt cch chi tit hn.

Thit lp iu kin lc

- Click nt Filter by Form hoc chn menu RECORDS - FILTER - ADVANCED FILTER / SORT

- Nhp iu kin lc vo hp thoi Advanced Filter / Sort: chn tn Field, nhp iu kin lc trong dng Criteria, b sung iu kin lc trong dng Or

- Cc iu kin lc trn cng dng c ngha l And. Thc hin lc : Click nt Apply Filter (hnh ci phu) trn

Toolbar hay Menu RECORD - APPLY FILTER / SORT. 3.2.3.5 B lc

Click nt Remove Filter (hnh phu) hay chn menu RECORD v chn REMOVE FILTER.

3.2.4 Sao chp Bng Sao chp Bng trong cng tp CSDL

Cch 1 - Chn Bng ri Ctrl+R - Bng sao chp c to vi tn l Copy of : t li tn

Bng cho ph hp. - Bng sao chp gm cu trc v d liu bng nh ngun.

Cch 2 - Chn Bng mun sao chp trong hp thoi Database v

Copy vo Clipboard (Ctrl+C hay chn menu EDIT - COPY)

- Dn Bng t Clipboard (Ctrl+V hay chn menu EDIT - PASE)

- Chn mc thch hp trong hp thoi Pase.

Microsoft Access

41

o Structure Only : Ch chp cu trc. o Structure and Data : Chp cu trc v d liu. o Append Data to Existing Bng : Ghi ni ui d liu

vo Bng ch c chn (phi chn Bng). Sao chp Bng qua tp CSDL khc Cch 1:

- Copy Bng ngun vo ClipBoard - M tp CSDL ch v dn (chn cch dn nh nu trn)

Cch 2: M c hai tp CSDL ngun v ch ri r Bng t CSDL ngun qua CSDL ch

3.2.5 Export Bng sang CSDL khc Chn Bng mun Export Chn menu

FILE EXPORT

Trong hp thoi Export To, chn tp tin CSDL ch.

Trong hp Export, chn cch Export Definition and Data : Chp c cu trc v D liu ca Bng

ngun. Definition Only : Ch chp cu trc Bng ngun.

3.2.6 i tn Bng Ti ca s Database, chn Bng cn i tn v thc hin mt

trong cc cch sau : chn menu EDIT - RENAME hay nhn phm tt F2 hay chn RENAME trn Shortcut Menu v nhp tn mi cho Bng.

Microsoft Access

42

BI TP: 1. To tp tin CSDL qun l ca hng mua bn vn phng phm

t tn l VPP.MDB

2. Trong tp tin VPP.MDB hy to cc table sau y Table KHACH_HANG: kha chnh l MAKH

Field Name Data Type

Field size

Field Properties

MAKH Text 4 Gm 1 k t K v 3 k s (ch K c lu trong field). Input Mask: \K000;0

TENKH Text 40 C nhp hin mu xanh, nu khng nhp th hin ch khch vng lai mu Format: @[Blue];Khch vng lai[Red]

DIACHI Text 50 DIENTHOAI Text 10 Input Mask: 000-0000

D liu nhp MAKH TENKH DIACHI DIENTHOAI K001 Cty TNHH Minh c 66 Trn Quang

Khi, Q3 8327890

K002 Cty Du lch ng Thp 365 in Bin Ph, Q10

8453612

K003 Khch sn Hng Sen 155 Nguyn nh Chiu, Q3

8384908

K004 X nghip in Bin 81 Lc Long Qun, TB

8456432

K005 Khch sn Hi Dng 60 Bach ng, Q1 8917645 K006 X nghip ng Tm 212 Hai B Trng,

Q1 8154981

K007 X nghip giy ng a 181 Trn Quang Diu, Q1

8651299

K008 Cty TNHH Hon Cu 254 An Dng Vng, Q5

K009 X nghip Dc phm 2/9

314 CMT8, Q3

K010 Cty giy dp Vina 489 Hng Vng, Q5

8235471

Microsoft Access

43

Table MAT_HANG: kha chnh l MAMH Field Name

Data Type

Field size

Field Properties

MAMH Text 3 Gm 1 k t V v 2 k s (ch V c lu trong field). Input Mask: \V00;0

TENMH Text 30 Tn mt hng DVT Text 10 n v tnh, nhp 1 ch u hoa, cn

li l ch thng. Input Mask: >L

Microsoft Access

44

3. Thit lp mi quan h gia cc Table, sau nhp d liu sau vo cc table MAT_HANG, HOADON, CHITIET_HD

Table MAT_HANG

MAMH TENMH DVT DONGIA V01 Bt ch Cy 13000V02 Bt lng vit bng Hp 55000V03 Giy vi tnh A4 Gam 36000V04 a mm 1,4MB Maxell Hp 45000V05 Bt bi Thin Long Hp 13000V06 Thc v Cy 8500V07 Kp giy Hp 7000V08 Ba h s Ci 28000V09 Bng keo 2 mt Cun 8500V10 Bt xa Cy 15000

Table HOADON SOHD MAKH NGAYDAT NGAYGIAO

001 K006 1/14/2006 1/15/2006002 K007 1/17/2006 1/21/2006003 K001 1/28/2006 1/30/2006004 K009 2/13/2006 2/13/2006005 K002 2/19/2006 2/26/2006006 K006 2/19/2006 2/22/2006

Table CHITIET_HD SOHD MAHH SOLUONG SOHD MAHH SOLUONG 001 V02 40 004 V01 150 001 V04 50 004 V05 180 001 V06 40 004 V10 50 001 V01 100 005 V08 200 002 V05 80 005 V03 60 002 V01 50 006 V03 200 003 V04 100 006 V04 60 003 V03 20 006 V05 50 003 V07 90 006 V06 20

4. Copy table MAT_HANG thnh table HANGHOA. 5. Export table HANGHOA ra file Excel. Xa table HANGHOA. 6. ng Access, m Excel v xem tp tin HANGHOA.XLS

Microsoft Access

45

CHNG 4

MI QUAN H GIA CC BNG 4.1 KHI QUT

4.1.1 Mi quan h (Relationships)

MS-ACCESS l h qun tr CSDL quan h (Relational Database Management System) nn c th s dng d kin ly t nhiu Bng khc nhau nu cc Bng ny c mi quan h vi nhau. Mun vy, phi khai bo mi quan h gia cc Bng lin quan.

Tc v khai thc: MS-ACCESS da vo mi quan h c nh ngha gia cc Bng thc hin cc tc v sau To lin kt trong cc Bng vn tin (Query). Hin th cc Mu tin c mi quan h trong biu mu con

(SubForm) hay biu bo con (SubReport). Bt but qu trnh khai thc d kin phi tn trng tnh ton

vn tham chiu d kin (Referential Integrity) bo v s quan h gia d kin ca cc Bng.

4.1.2 Quy nh mi quan h Quy nh mi quan h gia cc Bng bng cch khai bo mt hay

nhiu Field ca Bng ny m Field cha tr ging vi tr trong nhng Record quan h Bng kia.

Nhng Field i chiu trong cc Bng c quan h vi nhau thng c tn ging nhau, tuy nhin c th khng cng tn nhng phi cng kiu d liu v cha cng loi thng tin.

Cc Field thuc kiu number phi c xc lp thuc tnh FieldSize ging nhau.

Ngoi l : c th lin kt mt Field kiu AutoNumber vi mt Field kiu Number vi thuc tnh FieldSize ca chng l Long Integer hay ReplicationID

Trong nhiu trng hp, nh ngha s quan h bng lin h mc kha chnh ca mt Bng vi mt Field i chiu ca mt Bng khc.

4.1.3 Cc loi quan h

- Khi qut - Khai bo quan h

Microsoft Access

46

Mt -Nhiu (One To Many): mi Record ca mt Bng ny quan h vi nhiu Record ca Bng kia.

Mt - Mt (One To One): mi Record ca mt Bng ny quan h vi nhiu Record ca Bng kia.

Nhiu - Nhiu (Many To Many): khng th thit lp trc tip mi quan h nhiu - nhiu, cn c Bng trung gian thit lp quan h mt - nhiu.

4.2 KHAI BO QUAN H GIA CC BNG

4.2.1 Khai bo quan h ng tt c cc Bng ang m. Khng to hay hiu chnh cc

quan h gia cc Bng ang m. Mun quy nh mi quan h, phi m ca s Relationships.

4.2.1.1 Hin th ca sRelationShips ang ng ti ca s Database, Click nt Relationships trn

Toolbar hay chn menu Tools Relationships hin th Relationships. Ca s ny trnh by s quan h gia cc Bng

Nu l ln u tin khai boquan h th ca s Relationships trng v hp thoi SHOW TABLE c hin th.

Nu trc c nh ngha hay xem v iu chnh khai bo quan h th Access s hin th tnh trng cui cng ca ca s Relationships.

Mun hin th tt c cc quan h trong ca s Relationships: Click phi vo vng trng ca ca s Relationships v chn SHOW ALL

4.2.1.2 a Bng hay Query vo ca s RelationShips M hp thoi SHOW TABLE (nu cha m)

- Click phi vng trng ca s Relationships v chn SHOW TABLE

- hay chn menu VIEW SHOW TABLE - HAY Click nt SHOW TABLE trn Toolbar.

Chn phiu lin quan hin th d liu cn khai bo quan h: Table (hin th cc Bng), Queries (hin th cc Queries) hay Both (hay c Bng v Query)

a Bng / Query vo ca s quan h - Double Click tng Bng / Query tham gia vo mi quan h. - Hoc phi hp vi phm Shift hay Ctrl chn nhiu Bng ri

Click ADD. - Click Close ng hp thoi SHOW TABLE.

Microsoft Access

47

- Hoc nu nhn thy ca s Database v ca s Relationships: drag Bng / Query tham gia quan h t ca s Database vo ca s Relationships.

Lm n Bng / Query trong ca s Relationships ch c ngha khng hin th bng ny v cc mi quan h ca n vi cc Bng khc trong ca s Relationships (khng xo mi quan h c khai bo). - Chn Table / Query mun lm n - Chn Hide Table t Shortcut Menu hay t menu Relationships

hay nhn phm Delete. 4.2.1.3 Quy nh mi quan h gia cc Bng trong ca s Relationships

Drag Field t Bng chnh n Field ca Bng quan h. Hu ht trng hp l Drag t Field mc kha chnh (Primary Key) ca Bng chnh n Field mc kha ngoi (Foreign Key) ca Bng quan h.

Hp thoi Relationships hin th Field mc kha chnh thuc Bng chnh (Primary Table), Field i chiu thuc Bng quan h (Related Table). Click Create to mi quan h.

Hp thoi c ba phn - Phn trn tri gm 2 ct y Ghi tn Bng / Query chnh v Bng / Query quan h y Ghi tn cc Field c khai bo tham gia mi quan h.

- Phn di tri l cc mc chn xc lp v ton vn tham chiu cho 2 Bng quan h. y Enforce Referential Integrity: Nu nh du chn - thit lp

tnh ton vn tham chiu cho 2 Bng quan h. y Cascade Delete Related Records

Nu c thit lp tnh ton vn tham chiu v nh du chn mc ny - cho php Access t ng lp li (Cascade) tc v xa cc Record c quan h (Xa Record trong Bng chnh - xa cc Record quan h trong Bng quan h).

Microsoft Access

48

y Cascade Update Related Field Nu c thit lp tnh ton vn tham chiu v nh du chn mc ny - cho php Access t ng lp li (Cascade) tc v cp nht cc Field c quan h (thay i tr mc kha chnh - mc kha Field lin h cng c thay i).

- Cc nt lnh (phn bn phi) y Create : Ghi lu cc khai bo trong hp thoi ngha l thit

lp quan h hai Bng / Query y Join Type (kiu kt ni) : Khai bo trong hp thoi JOIN

PROPERTIES thuc tnh quan h ang khai bo. Mc nh l kiu kt ni s 1 (inner join - lin kt ni)

y Create New : Khai bo mi quan h mi

Nu mun to mi quan h ca mt Bng vi chnh n, thm Bng vo ca s Relationships mt ln na. Trng hp ny xy ra khi cn thc hin truy tm d liu trong cng mt Bng. V d : trong Bng tn Employees, mt mi quan h c nh ngha gia hai Fields tn EmployeeID v ReportTo, cho tn Field ReportTo ch hin th d liu ca mt employee t mt EmployeeID tng ng (Ni khc, mt nhn vin chu s qun l ca mt ngi v ngi ny cng l nhn vin Cng ty).

4.2.1.4 Vn ton vn tham chiu Khi nim

- Ton vn tham chiu l h thng cc quy tc c s dng bo m mi quan h gia cc mu tin trong cc Bng / Query quan h.

- Khi ton vn tham chiu c thit lp th khng th ngu nhin xa hay thay i cc d liu c quan h.

iu kin thit lp ton vn tham chiu - Field tng ng t Bng chnh l kha chnh hay ch mc duy

nht. - Field quan h c cng kiu d liu vi Field kha chnh (tr

ngoi l nu phn trn). - C 2 Table u phi thuc cng mt CSDL (Database) Access.

Microsoft Access

49

Cc quy tc cn tn trng khi lp ton vn tham chiu: - Khi nhp mt tr vo Field tng ng ca Table quan h th tr

ny phi c trong Field mc kha chnh ca Table chnh. - Khng th xo mu tin trong Table chnh nu trong Table

quan h tn ti mu tin c quan h vi mu tin mun xa. 4.2.2 Hiu chnh mi quan h c nh ngha

4.2.2.1 Hiu chnh mi quan h c nh ngha gia hai Table M hp thoi Edit Relationships

Click phi vo ng biu din mi quan h gia hai Table / Query v chn Edit Relationships hoc chn menu Relationships Edit Relationships hoc Double Click vo ng biu din.

Thc hin hiu chnh trong hp thoi.

4.2.2.1 Hy b mt quan h khai bo Click phi vo ng biu din mi quan h gia 2 Table chn

lnh Delete trn Shortcut Menu hay chn menu EDIT - DELETE hay Click chn ng biu din mi quan h cn hy b v nhn phm DELETE.

4.2.3 Hin th cc quan h nh ngha Mun hin th cc quan h khai bo - M hp thoi Relationships - Hin th tt c cc quan h : lnh SHOW ALL

4.2.4 SubDatasheet Khai mi quan h gia cc Bng c khai bo, nu m Bng

bn 1, ACCESS hin th k hiu du cng(+ : Expand indicator). Click vo Expand indicator hin th Bng lin kt bn nhiu. Bng ny c gi l SubDatasheet.

Microsoft Access

50

BI TP: 1. To tp tin CSDL qun l qun l chm cng tnh lng cho

cng nhn t tn l QLCN.MDB 2. Trong tp tin QLCN.MDB hy to cc table sau y Table SANPHAM c cu trc: kha chnh l MASP

Field Name Data Type Field size Yu cu MASP Text 4 Qui nh nhp 1 ch 3

s, ch vit hoa. TENSP Text 30 Tn sn phm, ch u

vit hoa, cn li thng DONGIA Number Long Integer n gi sn phm, t

1000 n 50000 D liu nhp:

MASP TENSP DONGIAA001 Ao smi n 15000A002 Ao smi nam 25000A003 Ao khoc 35000B004 Bao tay 5000N005 Nn 7000Q006 Qun ty n 25000Q007 Qun ty nam 35000Table CONGNHAN c cu trc: kha chnh l MACN

Field Name

Data Type Field size Yu cu

MACN Text 3 M cng nhn, qui nh nhp 3 s

HOTEN Text 40 H tn cng nhn PX Number Byte Phn xng, ch c nhp t

1 n 10 Table CHAMCONG c cu trc: kha chnh l MACC

Field Name

Data Type Field size Yu cu

MACC Number Long Integer

M chm cng

NGAY Datetime Ngy chm cng, nh hn hoc bng ngy hin ti

MACN Text 3 Combo box chn t Table CONGNHAN

Microsoft Access

51

Table CHITIET c cu trc: kha chnh l MACC v MASP

Field Name

Data Type Field size Yu cu

MACC Number Long Integer

M chm cng

MASP Text 4 Combo box chn t Table SANPHAM

SOSP Number Integer S sn phm, ln hn khng SOPP Number Integer S ph phm, nh hn s sn

phm Chn menu View Properties Validation Rule: [SOPP] < [SOSP] Validation text: S ph phm phi nh hn s sn phm

3. Lin kt cc Table v nhp d liu sau Table CONGNHAN

MACN HOTEN PX001 Nguyen Thuy Van 1002 Le Hai Viet 1003 Tran Binh 2004 Phan Van Thanh 2005 Tran Vinh Huy 2006 Nguyen Ngoc Han 3007 Tran Van An 3

Table CHAMCONG

MACC NGAY MACN1 14/09/05 0012 14/09/05 0023 14/09/05 0034 25/09/05 0045 25/09/05 0056 11/10/05 0037 11/10/05 0048 22/10/05 0059 22/10/05 00110 22/10/05 006

Microsoft Access

52

Table CHITIET

MACC MASP SOSP SOPP 1 A001 25 11 N005 40 02 A001 30 02 Q006 15 03 Q007 60 24 B004 80 54 A002 20 04 A003 50 25 Q006 70 06 Q007 120 47 A002 70 07 Q007 50 18 B004 40 08 Q007 20 28 N005 15 09 A003 45 410 N005 30 010 Q006 20 0

Microsoft Access

53

CHNG 5

TON T - BIU THC - HM

5.1 TON T 5.1.1 Ton t s hc Ton

t Php ton C php Cng dng

+ Cng Kt qu = s 1 + s 2 Cng hai gi tr s. Cng c th dng ni hai chui k t

- Tr Kt qu = s 1 - s 2 Tr hai gi tr s. C th dng biu din mt s m

* Nhn Kt qu = s 1 * s 2 Nhn hai gi tr s / Chia Kt qu = s 1 / s 2 Chia hai s c s l thp

phn \ Chia

nguyn Kt qu = s 1\ s 2 Chia hai s nguyn v ly

phn nguyn ^ Ly tha Kt qu = s ^ s m Ly tha mt s. V d: 3^2

9 Mod Phn d

php chia Kt qu = s 1 MOD s 2

Tr v phn d mt php chia chn. V d: 23 MOD 7 2

5.1.2 Ton t so snh Tr v tr True / False. Cc ton hng phi cng kiu d liu

Ton t Php ton C php

= So snh bng Ton hng 1 = Ton hng 2 > So snh ln hn Ton hng 1 > Ton hng 2 < So snh nh hn Ton hng 1 < Ton hng 2 >= So snh ln hn hay bng hn Ton hng 1 >= Ton hng 2

Microsoft Access

54

5.1.3 Ton t chui

Ton t Php ton C php

& Ghp chui Chui 1 & Chui 2 Nu ton hng khng phi l chui s mc nhin xem nh chui v kt qu nhn l mt chui. Nu c hai ton hng l Null tr tr Null Nu ch mt ton hng l Null xem nh mt chui vi di l 0

Like So snh chui

Biu thc Like khun mu c dng cc k t i din ca DOS trong biu.

V d v ton t Like Nhp biu thc sau vo dng Criteria ca li QBE khi thit k

Query: Like [Enter the First Letters of the Name]&* : nhp cc k t u ca tn Like P[A-F]### : k t u l P, k t th hai trong khong A n F v 3 k t cn li l ch s. Khi tham chiu n mt iu khin, hy bao cc danh hiu iu

khin trang du nhy kp v cc vch thng ng:

Like [Forms]![In don dat hang]![Ma don hang] Nu khng thm cc du vnh ng, ton t Like ttr v tn iu khin thay v tr v tr ca iu khin.

Nu s so khp thnh cng, tr TRUE (-1) tr v, ngc li l tr FALSE (0). Nu biu thc c tr Null th kt qu cng l Null.

5.1.4 Ton t Logic Ton t Php ton v c php And Hi (Conjunction)

Biu thc 1 AND Biu thc 2 Eqv Tng ng (Equivalent)

Biu thc 1 EQV Biu thc 2 Nu biu thc l Null, kt qu cng l Null

NOT Ph nh Or Php tuyn Logic Xor Php tuyn loi tr Imp Bao hm (Implication)

Microsoft Access

55

5.1.5 Ton t khc

Ton t ngha ! L ton t danh hiu. Theo sau l tn mc do

ngi dng nh ngha (nh biu mu, bo co, cc iu khin v cc Field) V d: Forms![San pham]![Gia don vi]

.(dot) L ton t danh hiu. Thng c theo sau bi mt tn tnh cht. V d: Forms![Customers].Visible

[] Du bao tn cc mc BetweenAnd Xc nh gi tr mt biu thc c nm trong vng gi

tr c ch nh hay khng V d: Lc cc Record c tr ca Field soluong trong khong 50 n 100. Ti dng Criteria ca Field ny trong QBE ghi nh sau: Between 50 And 100

In Xc nh gi tr mt biu thc c bng vi mt trong nhiu tr trong mt danh sch c ch nh hay khng V d: Lc cc Record c tr ca Field CountryID l cc m US, UK, FR, JP. Ti dng Criteria ca Field ny trong QBE ghi nh sau: In(US, UK, JP, FR) =IIF([Ship Region] In (Avon, Glos, Sorff), Local, Non Local)

Is Dng t kha NULL xc nh biu thc c tr Null hay khng =IIF(Forms![My Form]![My Control] Is Null, No Entry, Forms![My Form]![My Control])

*? K t i din ca DOS (thng dng vi Like) du * thay th mt nhm k t bt k du ? thay th mt k t bt k

5.2 BIU THC 5.2.1 Khi qut

L thnh phn c bn ca nhiu php ton ca Access, dng ch nh tiu chun cho cc vn tin, lc v cc macros.

V d: dng biu thc to mt Calculated Field:

Thanhtien:[Dongia]*[Soluong]

Thue: [Dongia]*[Soluong]*10/100

Microsoft Access

56

5.2.2 Thnh phn ca biu thc L t hp gm cc ton t, danh hiu, cc hm, cc tr literal v cc

hng Phn

t V d M t

Ton t

=,

Microsoft Access

57

YEAR (date) : tr ra 1 gi tr t 100 .. 9999 l nm ca date WEEKDAY (date) : Tr ra 1 gi tr t 1 n 7 l Th ca date,

vi 1 l Sunday, 2 l Monday, , 7 l Saturday

DATEADD (chui, s, ngy) : tr v thi im l mt ngy no sau khi cng thm khong thi gian vo. Trong chui qui nh khong thi gian cng l loi g (d l ngy, m l thng, y l nm)

HOUR (date) : Tr ra 1 gi tr t 0 .. 23 l Gi ca date MINUTE (date) : Tr ra 1 gi tr t 0 .. 59 l Pht ca date SECOND (date) : Tr ra 1 gi tr t 0 .. 59 l Giy ca date

5.3.3 Cc hm chui

LEN (chui) : tr ra di ca chui (s k t c trong chui) CHR (s) : tr ra 1 k t c m ASCII bng s

V d: Chr(65) tr ra k t A

INSTR (start, S1, S2) : Tr ra 1 s l v tr xut hin u tin ca chui S2 trong chui S1, vi start l v tr bt u tm trong S1, S1 l chui cn tm, S2 l chui tm trong S1. V d: Instr(5,con g con cn con g,con) s tr v s 8 l v tr xut hin ca con trong chui.

LCASE [$] (chui) : i chui thnh chui mi c cc k t l ch thng.

UCASE [$](chui) : i chui thnh chui mi c cc k t l ch in.

LEFT [$](chui, N) : Ct N k t bn tri ca chui. RIGHT [$](chui, N) : Ct N k t bn phi ca chui. MID [$](chui , v tr , s) : Ct s k t trong chui tnh t v tr

tr i. Nu khng c s th ct t v tr cho n ht chui.

LTRIM | RTRIM | TRIM [$] (chui) : ct cc khong trng bn tri, bn phi, c 2 bn ca chui.

SPACE (N) : tr v 1 chui c N khong trng STRCOMP (S1, S2) : tr ra gi tr 1 (true) hoc 0 (false) phn

nh kt qu so snh 2 chui ging nhau (-1 l S1 khc S2 , v 0 l S1 ging S2).

Microsoft Access

58

V d : a = Strcomp(abc,xyz) th a c gi tr = -1

STRING (N , k t) : tr ra 1 chui gm N k t . 5.3.4 Cc hm s hc ABS (s) : tr ra gi tr tuyt i ca s. ASC (chui) : Tr ra m ASCII ca k t u tin trong chui. SIN , COS , ATN , TAN (s) : Tr ra Sin , Cos , Arctan , Tan ca

s theo Radiant. EXP(s) : Tr ra e ly tha s INT, FIX (s) : Tr v phn nguyn ca s. Nu s < 0 (m) th

FIX tr v s nguyn ln hn hoc bng s , cn INT tr v s nguyn c gi tr nh hn hoc bng s.

SQR (s) : tr ra cn bc 2 ca s. VAL (chui) : i chui thnh s

5.3.5 Cc hm c s d liu DAVG (exp, domain, [criteria]) : tnh trung bnh cc gi tr ca

cc record trong domain tha theo criteria. exp : chui cha tn field cn tnh domain : chui cha tn table hoc query cn tnh criteria : chui cha 1 iu kin.

V d: Davg([SOLG], [CT BAN LE] , [DGL] >=1000) l tnh trung bnh Field SOLG trn bng CT BAN LE theo iu kin c DGL >= 1000.

DMAX , DMIN (exp , domain , [criteria]) : ly gi tr ln nht, nh nht trong exp ca domain.

V d: Dmax ([SOLG] , [CT BAN SI] , [MAHG] = 001) tc l ly gi tr ln nht trong field SOLG ca bng CT BAN SI theo iu kin MAHG l 001.

DFIRST, DLAST (exp , domain , [criteria]) : ly gi tr u tin, cui cng trong exp ca domain tha theo criteria.

DCOUNT (exp , domain , [criteria]) : m cc record ca exp trong domain tha criteria.

DSUM (exp , domain , [criteria]) : tnh tng cc record ca exp trong domain tha criteria.

DLOOKUP (exp, domain, [criteria]) : Tr v gi tr ca exp trong domain tha criteria.

Microsoft Access

59

BI TP: 1.Cho bit kt qu ca cc hm sau y:

- LEN(Microsoft-Access) - LEFT(Tin hc,3) - RIGHT(Cao Thng,5) - MID(Microsoft-Access,5,3) - DATE() - MONTH(DATE()) - YEAR(DATE()) - DAY(DATE()) - WEEKDAY(DATE()) - SQR(5) - INT(17.5) - FIX(17.5) - INT(-20.4)

2.Cho bit ngha ca cc biu thc sau, vi [HO], [TEN], [NGAYSINH], [PHAINU], [DIEM] l cc field trong table HOCSINH:

- YEAR(DATE()) YEAR([NGAYSINH]) - UCASE([HO] & & [TEN]) - IIF(Weekday(Date())=1,Ch nht,Th & Weekday(Date()) - IIF([PHAINU]=Yes, N, Nam) - IIF([DIEM]

Microsoft Access

60

CHNG 6

TRUY VN (QUERY)

6.1 KHI QUT V QUERY

6.1.1 Query l g

Query l cng c ca Access dng khai thc d liu trn mt hay nhiu Bng / Query khc bng cch thc hin cc yu cu truy vn.

Ngi s dng nu cc cu hi (yu cu tuy vn) v Access s thc hin vic truy tm d liu theo yu cu trn nhng Bng / Query ch nh v tng hp d liu cho cc thng tin cn thit trn mt Bng gi l Bng d liu ng (Dynamic Set hay DynaSet)

Query cng c dng nh mt ngun d liu cho cc cng c khc nh FORM, REPORT hay QUERY khc.

Mun thc hin Query, phi c Database vi mt hay nhiu Bng .

Nu thc hin hiu chnh trn Query th s liu trn cc Bng cng c sa i theo.

6.1.2 Cc trng hp s dng Query

Thng s dng Query trong cc trng hp sau: La chn cc Field cn thit (khng cn bao gm tt c Field

ca Bng) La chn nhng tin theo tiu chun no . Xp th t cc tin Tham kho d liu ca nhiu Bng khc nhau. Thc hin cc php tnh. To d liu c s cho Form, Report hay Query khc.

6.1.3 Cc loi Query

C th tm phn loi cc Query thnh cc loi nh sau : Select Query, Action Query, Crosstab Query v mt s loi khc.

- Khi qut v Query - Thit k query - Cc ch hin th Query - Thao tc vi Query - Query Wizard

Microsoft Access

61

6.1.3.1 Select Query (La chn) S dng kh ph bin. Loi Query cho php - Vn tin trn nhiu Bng d liu - To ra Field tnh ton (Calculated Field) - Kt nhm d liu - Chn Field cn hin th hoc khng hin th d liu.

6.1.3.2 CrossTab Query (Tham kho cho) - Dng tng hp d liu theo chng loi (tng s, s lng,

tr trung bnh,) theo dng bng tnh (c tiu ct dng v kt qu tng hp).

- Loi ny t ra hu ch trong vic phn tch d liu v to cc biu da trn tng gi tr ca cc Field s ca nhiu tin.

6.1.3.3 Action Query (hnh ng) Loi Query ny cho php thc hin nhng thay i vi

nhiu tin trong cng mt tc v, to cc Bng mi, hiu chnh hay xa tin. Ty theo cng dng, cc Action Query gm: - Delte Query: Xa nhm tin t mt hay nhiu Bng. - Update Query: Cp nht nhm tin cho mt / nhiu Bng. - Append Query: Ni thm d liu t cc tin ca mt hay nhiu

Bng vo phn cui ca mt Bng. - Make-Table Query: to mt Bng t mt phn hay tt c d

liu trong mt hay nhiu Bng khc.

6.1.4 Query c s dng tham s (Parameters) Nu c mt Query dng vo bt k mc ch no (nh Select,

Update, Delete,) m khi thc cn phi nhn cc tr tham s to ra kt qu th Query c s dng tham s.

Cc tham s dng cho Parameter Query c xem nh nhng tr cha th xc nh vo lc thit k v c ghi di dng mt tn bin (khai bo ti dng Criteria ca Field lin quan).

V d: mun to bo co trong khong thi gian no , ghi dng Criteria di ct NGAY ca Bng Query nh sau :

Between [so lieu tu ngay :] And [Den ngay :]

Cc t hp [so lieu tu ngay :] v [Den ngay :] l nhng tn bin dng to tham s cho Query.

6.1.5 Mt s Query c bit khc

Union Query: Nhm ni ui cc d liu t hai hay nhiu Bng thnh mt danh sch xem chung.

Microsoft Access

62

PassThrough Query: Dng gi lnh tc tip n mt CSDL h ngn ng vn tin nh Microsoft SQL Server hay Sybase SQL Server.

Data-Definition Query: Dng ngn ng SQL to hay sa i cu trc mt Bng trong Database.

SubQuery: Gm mt pht biu SQL SELECT trong mt Select Query hay Action Query khc.

Find Duplicate Query: Tm trong Bng cc mu tin trng lp trn gi tr ca mt hay nhiu Field.

Find UnMatched Query: Tm cc mu tin trong mt Bng d liu khng c quan h vi mt mu tin trong Bng quan h.

6.2 THIT K QUERY

C hai cch thit k Query

6.2.1 Dng Query Wizard Query Wizard dng thit k nhanh mt Query. Phng php ny c hn ch v ch thit k c mt s Query. Ty theo loi Query cn thit k (Simple Select, CrosstTab,)

thc hin theo cc bc hng dn ca WIZARD. 6.2.2 Thit k Query vi Design View

y l trng hp T thit k Query m khng dng Wizard (cn gi l thit k From Scratch) thng qua ca s Design View. Cc bc khi qut t to mt Query: Khi ng Design View Chn cc Bng, Query tham gia yu cu truy vn. Khai bo mi lin h gia cc Bng (nu trc cha khai

bo), khai bo cc tiu chun lc (nu cn) Chy th v ghi lu.

GHI CH : C th phi hp hai phng php trn bng cch to Query vi WIZARD trc ri hiu chnh li bng Design View. 6.3 CC CH HIN TH QUERY

Ca s Query c 4 ch hin th.

6.3.1 Datasheet View L dng hin th chun khi chy Query (nh dng hin th ca

Bng) gm dng u tin l tn cc Field v cc dng cn li l cc mu tin.

Thao tc

Microsoft Access

63

- Trong ca s Database, chn Query cn hin th ri Click Open.

- Hoc nu ang hin th Query dng Design View hay SQL View th chn lnh View - Datasheet View trn Menubar hay trn Shortcut Menu.

Trong khi thit k Query, c th dng Datasheet View xem th kt qu thit k (Chn lnh View - Datasheet View trn Menubar hay trn Shortcut Menu).

6.3.2 Design View Hin th Query theo dng thit k. Dng thit k hay hiu

chnh Query. 6.3.2.1 Thao tc Trong ca s Database, chn Query cn hin th v Click

Design View trn Toolbar ca ca s hay trn Shortcut Menu. Hoc nu ang hin th Query dng Datasheet View hay

SQL View th chn lnhView - Design View trn Menubar hay trn Shortcut Menu.

6.3.2.2 Ca s Design View C hai khung gm

Khung trn : Khung cha d liu ngun. Hin th cc Bng

tham gia Query v mi quan h gia chng (nu c). Khung di : gi l li QBE (Query By Example) dng

nhp yu cu vn tin cho Query 6.3.2.3 Thuc tnh Field ca Query Khai bo thuc tnh Field trong ca s thuc tnh ca Field. M ca s thuc tnh ca Field

Khung cha d liu ngun

Khung li QBE

Microsoft Access

64

- Click phi vo Field lin quan trn li QBE v chn Properties.

- Hay ng ti Field lin quan v chn menu View Properties.

- Hay ng ti Field lin quan v nhn ALT+ENTER Cc thuc tnh

- Description: Cha chui k t m t Field - Format: Quy nh dng thc hin th ni dung Field. - Input Mask: Quy nh dng thc nhp liu vo Field - Caption: Cha chui k t lm nhn cho Field.

6.3.2.4 Thuc tnh ca Query Khai bo cc thuc tnh cho Query trong ca s thuc tnh

ca Query M ca s thuc tnh ca Query

- Khng ng ti Field no ca Query: chn menu View v chn Properties hay nhn ALT+ENTER

- Hay Click phi vo vng khng thuc Field no c v chn Properties trn Shortcut Menu.

Cc thuc tnh - Description : M t Query - Default View : Ch hin th mc nh - Output All Fields : Hin th tt c Field - Top Values : Hin th cc tr u tin - Unique Values : Hin th tin m tt c tr cc Field ca

Query l duy nht

Microsoft Access

65

- Unique records : Khng hin th tin trng lp 6.3.3 SQL View Hin th thit k Query di dng dng lnh theo ngn ng

SQL. Cc dng lnh ny do Access to ra khi thit k Query hay do ngi dng khai bo.

Thao tc: M Query trong ch Datasheet View hay Design View v chn lnh View-SQL View trn Menubar hay trn Shortcut Menu.

6.3.4 Print PreView L ch xem trc khi in (Kt qa hin th ging nh khi in).

Ch Query cn hin th trong ca s Database hay m Query theo ch Datasheet View.

Chn lnh Print Preview t menu VIEW hay Shortcut Menu. 6.4 THAO TC VI QUERY

6.4.1 Ghi lu vi Query Nh mi i tng khc, Query sau khi hon tt thit k hay

hiu chnh phi c ghi lu. Ghi lu : FILE - SAVE hay Ctrl+S hay Click biu tng ghi

lu v t tn cho Query trong hp thoi Save As. Tng t nh Bng, Query l mt thnh phn ca CSDL nn

sau khi c thit k v ghi lu, Query c t trong ngn QUERIES ca Database Container.

6.4.2 Thao tc vi Query C th thc hin tc v sao chp, sa cha, xa v.v. trn

Query (tng t thao tc vi Bng). Sa i thit k trong QUERY : Chn tn Query cn hiu chnh

ri click biu tng Design trn ca s Database. Thi hnh mt Query : Chn tn Query lin quan - Open (hay

Double Click) hay trong ca s Design View, click biu tng RUN trn thanh dng c

Query c th c kch hot thng qua lnh Macro. Trong mi trng nhiu ngi s dng

- Mun xem Query vi kt qa mi nht : Shift + F9 (Record - Refresh).

- Nu ang hiu chnh trong Query Design li c ngi khc hiu chnh Query Design (trong mi trng nhiu ngi dng), Access s thng bo cho bit v chn mt trong hai cch : hoc chp nhn nhng sa i y hoc lu thit k vi bng tn mi.

Microsoft Access

66

6.5 QUERY WIZARD 6.5.1 Gii thiu

Query Wizard l cng c gip tin hnh nhanh vic thit k mt Query v thng c i vi nhng loi Query sau Simple Query : Sellect Query n gin Crosstab Query : Vn tin tham kho cho. Find Duplicate Query : Vn tin tm tin trng lp. Find Unmached Query : Vn tin tm cc tin trong mt Bng d

liu khng c quan h vi mt Record trang Bng quan h (V d tm nhng khch hng cha c n t hng)

6.5.2 Cc bc chung to Query bng Query Wizard Bc 1: M CSDL lin quan. Bc 2: Trong ca s Database

- Chn loi i tng QUERIES - Hoc chn menu View - Database Object - Queries

Bc 3: M hp thoi New Query. - Click nt New trong Database Container - Hoc chn menu INSERT - Query - Hoc Click nt Dropdown cnh biu tng New Object :

trn Toolbar - chn Query trong Menu Dropdown.

Bc 4: Chn loi Query mun to trong hp thoi New Query. 6.5.3 To Query vi Simple Query Wizard

6.5.3.1 Khi ng Simple Query Wizard Chn mc Simple Query Wizard trong hp thoi New Query

6.5.3.2 Cc bc ca Wizard Chn Bng / Query v Field tham gia Query

- Chn Bng hay Query trong khung Table / Queries

Microsoft Access

67

- Chn cc Field tham gia trong khung Available Field v chuyn sang (click nt > bn cnh) khung Selected Field.

- Nu chn tt c Field th click nt >> - Click nt < hay

Microsoft Access

68

BI TP: 1. M tp tin VPP.MDB ra v chn trang Queries, thc hin cc

truy vn sau: - Lit k cc khch hng Q1.{ like*q1} - Lit k cc khch hng khng c s in thoi {is null}. - Lit k cc mt hng c n gi di 100000 {

Microsoft Access

69

CHNG 7

SELECT QUERY 7.1 THIT K SELECT QUERY

Select Query c dng kh nhiu lc, tng hp d liu t mt n nhiu Bng / Query khc v lm d liu ngun cho Biu mu, Bo biu. S dng Query Design View to Select Query nh sau:

7.1.1 M ca s Design View M CSDL lin quan - m Phiu Query - chn mc Design View

trong hp thoi New Query. Ca s QUERY DESIGN VIEW c hin th vi tn trn Tittle

gm :SELECT QUERY (Tn Query mc nh l QUERY#).

7.1.2 Ca s QUERY DESIGN VIEW Ca s thit k Query c 2 khung: Khung trn (cha cc Bng d

kin c chn tham gia vo Query) v Khung di (Li QBE (Query By Example) cha cc Field c a vo Query). Cc dng ca li QBE gm: Dng Field: ghi tn Field c a vo li Dng Table: ghi tn Bng/Query ca Field ch nh ti dng Field

(nh du chn mc Table Names trn Menu VIEW) Dng Sort: dng sp xp cc mu tin Dng Show: cha Check Box xc nh hin th / khng hin th

Field lin quan Dng Criteria: dng khai bo tiu chun lc Dng OR: dng khai bo b sung iu kin lc V ty loi Query, mt s dng khc s c hin th. 7.1.3 a d liu ngun vo ca s thit k a d liu ngun vo ca s thit k

- Thit k Select Query - Khai bo quan h - Tiu chun la chn - Calculated Field - Query Tng cng Nhm - Summary Query - Cc vn b sung

Microsoft Access

70

- T hp thoi SHOW TABLE, chn Tn Bng/Query lin quan v click ADD hoc double click tn Bng/Query a thm vo ca s thit k.

- Ch a vo ca s thit k cc Field ca Bng/Query cn s dng

a Bng d kin ra khi Query - Chn biu tng Bng mun a ra khi ca s Design

phn trn ca s thit k ri nhn phm Delete - Hay chn Remove Table trn Shortcut Menu

Khai bo quan h gia cc Bng/Query - Khi a vo ca s thit k hn mt Bng/Query, quan h

gia cc d liu ngun s t ng hin th nu quan h c t khai bo trc .

- Ngc li c th khai bo quan h ngay trong ca s Query. Cch khai bo cng tng t nh khai bo khi thit k Bng.

7.1.4 a cc Field ca cc Bng/Queries tham gia Query vo li QBE

7.1.4.1 a Field d liu vo li QBE Khi qut

- Field no ca Bng d kin cn s dng trong Query u a vo li QBE

- Mt Field c a vo li c th khng c hin th. Cch chung

Ln lt chn Field t cc Bng khung trn ca s thit k Query v ko vo li QBE hoc double click tn Field.

Thao tc nhanh - a tt c Field vo li y Chn tt c Field ca Bng d kin: double click tiu

biu tng Bng/Query y R vo li QBE: tt c Field s c a vo li

- a mt Field vo li y Double click mt Field, Field y c a vo li y Hay r th vo li y Hay ti ct tng ng, m v chn tn Bng/Query

dng Table, chn tn Field dng Field - a nhiu Field vo li cng lc y Chn cc Field mun a vo li y R th vo li

- R /double click du hoa th (*) y Biu th chn tt c Field nhng trong li ch c mt ct

cha du hoa th v tn Bng (V d: HOCSINH.*)

Microsoft Access

71

y Dng phng php chn du hoa th c li im l khng cn sa i Query khi thay i Field ca Bng c s (k c thm Field mi, Query t ng c cp nht).

7.1.4.2 Sp xp th t, chn, xa, thay i b rng cc Field trong QUERY

Thay i v tr Field: click Column Selector chn Field mun

thay i v tr ri ko n v tr mi. Thm Field mi: double click Field mun thm trn Bng thch

ng ri iu chnh v tr (nh nu trn) Xa Field: chn Field cn xa - nhn phm Delete hay chn

lnh Delete t Menu Edit. Thay i b rng Field: ko hay double click b phi Column

Selector ca Field tng ng.

7.1.4.3 Khai bo th t sp xp cc tin ng trong dng SORT ca Field cn xp th t - click

Dropdown v chn cch sp xp (Not Sorted: khng xp th t, Ascending: tng dn, Descending: gim dn)

7.1.5 Ch nh Field c hin th nh du chn hay b chn Checkbox ti dng Show ca Field

lin quan (nh du chn: hin th Field)

7.1.6 Khai bo tiu chun vn tin (Criteria)

7.1.6.1 Khi qut

Column Sector

Microsoft Access

72

Khai bo tiu chun vn tin ch nh phm vi hin th cc mu tin. Ch nhng mu tin tha cc tiu chun ch nh mi c hin th.

Tiu chun vn tin c khai bo trn dng Criteria ca Field tng ng trong li QBE.

C hai cch khai bo tiu chun vn tin: nhp trc tip vo dng Criteria hay dng Expression Builder.

7.1.6.2 Khai bo bng Expression Builder M hp thoi Expression Builder

- ng trong dng Criteria ca Field cn khai bo - Click biu tng Build trn Toolbar hay lnh Build trn

Shortcut Menu - Nu CSDL c nhiu Builder, Access hin th hp thoi

CHOOSE BUILDER chn Expression Builder. Hp thoi Expression Builder

- Hp khai bo biu thc (trn) - Cc nt ton t (gia) - Hp cc phn t ca biu thc (di) gm 3 khung

y Khung tri: cha cc Bng, Folders cha cc hm, cc

biu thc thng dng y Khung gia: lit k cc phn t hng mc ca thnh phn ang chn bn tri.

y Khung phi: lit k cc tr ca mc chn tri v gia. mun a cc tr khung ny vo hp biu thc: double click tr lin quan.

7.1.6.3 Trc tip khai bo tiu chun trong QBE

Hp khai bo biu

Cc nt ton t

Hp cc phn t ca biu thc

Microsoft Access

73

Nhp trc tip biu thc tiu chun vo dng Criteria. Nhn Shift+F2 m ca s Zoom cho d nhp. Nhp biu thc tiu chun

- D kin kiu s hc (Number, Currency, AutoNumber): nhp bnh thng. Khng c s dng du phn cch hng ngn v du tin t.

- D kin kiu ngy/gi: phi theo Control Panel v c th khng dng k t ro # (V d:

Microsoft Access

74

R Field thuc Bng/Query th nht vo Field lin kt tng ng trong Bng/Query th hai. Quan h c thit lp khng c tnh ton vn tham chiu (ng ni khng c du 1- )

Cc cch lin kt Lin kt cht hoc tng ng (Inner-Join hay Equi-Join)

L kiu lin kt trong ch a vo Query nhng mu tin ca 2 Bng/Query c tr vng lin kt bng nhau.

Lin kt khng cht (Outer Join) L kiu lin kt trong nhng mu tin ca Bng/Query th nht c a vo Query ngay c khi n khng c mu tin i chiu Bng/Query th hai v nhng mu tin ca Bng/Query th hai ch c a vo Query khi chng c mu tin i chiu Bng th nht. Kiu lin kt ny c 2 loi. LEFT OUTER JOIN

L kiu lin kt trong tt c mu tin thuc Bng/Query c khai bo phn bn tri (LEFT JOIN) c a vo Query. Trong ca s Query, kiu lin kt ny c biu th bng ng ni mi tn bn tri.

RIGHT OUTER JOIN L kiu lin kt trong tt c mu tin thuc Bng/Query c khai bo phn bn phi (RIGHT JOIN) c a vo Query. Trong ca s Query, kiu lin kt ny c biu th bng ng ni mi tn v bn phi.

T lin kt (Seft-Join) L kiu lin kt mt Bng vi chnh n (a Bng ny vo Query hai ln). Mt mu tin trong Bng c lin kt vi nhng mu tin khc ca chnh Bng . Vi lin kt ny, tt c nhng Record trong Bng m Field lin kt c tr bng nhau u c a vo Query.

7.2.3 Thm Bng trung gian vo Query Khi a vo Query hai Bng/Query nhng chng li khng c

Field lin quan to mi lin kt, trong trng hp ny, phi a thm Bng trung gian vo Query ri thit lp mi lin kt gia chng. 7.2.4 Tm kim thng tin t ng (AutoLookup) Gi s mt khch hng quen thuc ( ng k) mua hng ca

mt cng ty, khi nhp d liu vo, khng cn nhp chi tit v khch hng v thng tin ny c lu trong tp tin KHACHHANG.

Vi cch thit k Query trong s dng cng c AutoLookup, ch cn nhp m s khch hng, cc chi tit lin quan n khch hng ny s c Access tm kim.

Microsoft Access

75

Tc v AutoLookup ch lm vic vi nhng Query trong hai Bng c s c quan h kiu One-To-Many v Field lin kt thuc Bng d kin pha One l Field ch mc duy nht hay Primary key.

7.3 S DNG TIU CHUN LA CHN TRONG QUERY 7.3.1 S dng k t i din

Dng k t i din trch chn cc Field c tr l chui k t hay Date/Time.

Tuy nhin, i vi d liu Date/Time th nn dng hm DatePart trong tiu chun th tc x l s nhanh hn.

Vi v d Biu thc tiu chun Access hin th Tm nhng tr Sm?th Like Sm?th Smith, Smyth L*ng Like L*ng Ling, Levering, Laka

Travel and Trading, *th Like *th 128th, Perth, */10/93 Like */10/93 tt c ngy ca thng 10/93

7.3.2 Trch nhng mu tin khng khp vi mt tr khai bo

Dng ton t NOT trong biu thc tiu chun. V d:

NOT H* hay NOT LIKE H* : nhng mu tin c k t u khng phi l H

NOT 2 : nhng mu tin c tr khng phi l 2

7.3.3 Biu thc tiu chun khai bo nhiu iu kin

Nhiu iu kin i vi mt Field S dng cc ton t And, Or thit lp nhiu iu kin cho mt Field. V d: Like The* And Like Box* hay

Davolio Or Buchanan

Nhiu iu kin i vi nhiu Field Ln lt khai bo cc tiu chun cho cc Field v theo tiu chun sau: - Cc tiu chun trn cng dng: iu kin AND - Cc tiu chun trn khc dng: iu kin OR

7.3.4 Trch mu tin c hoc khng c d kin

Microsoft Access

76

Dng biu thc NOT NULL hay IS NOT NULL cho Criteria trch mu tin ca Field c d kin.

Dng biu thc NULL hay IS NULL cho Criteria trch mu tin ca Field khng c d kin.

7.3.5 Trch mu tin ng vi ngy hin hnh ca my hay 1 danh sch Nhp hm DATE() vo dng Criteria trch nhng Record ng

vi ngy hin hnh ca my tnh. Dng ton t IN (tn1, tn2,) trch mt tr trong danh sch.

Danh sch c ghi trong cp ngoc n ca ton t IN v phn cch nhau bi du phy. V d: In (France, Germany, Japan)

7.3.6 Khai bo cc php tnh trong biu thc tiu chun C th khai bo cc php tnh trong Field tiu chun, c bit l

vi Field Date/Time. V d: Between DATE() And DATE()-5 Trong biu thc tiu chun, mun tham chiu n tr ca mt

Field khc th ro tn Field bng du ngoc vung []. V d:

Microsoft Access

77

CompanyName >=N Len([CompanyName])>Val(30)

Hin th n t hng gi n cng ty c tn bt u t ch N n Z Dng hm Len hin th nhng n t hng ca cng ty c tn di hn 30 k t

OrderID Right([OrderID],2)=99 Dng hm Right hin th cc n t hng c tr ca OrderID kt thc l 99

Dng tr DATE l tiu chun Field Biu thc Din gii

RequiredDate Between Date() And DateAdd (m,3,Date())

Hin th n t hng yu cu giao hng t ngy hm nay n 3 thng ti

OrderDate

Microsoft Access

78

7.4 TO FIELD TNH TON (CALCULATED) TRN QUERY 7.4.1 Khi qut

C th to Field tnh ton trn Query bng cch kt hp 2 hay nhiu Field khc ca Bng c s.

Access t ng t tn cho cc Field tnh ton l Expr1, Expr2 v sau ngi dng c th t li bng tn c ngha hn.

7.4.2 Cc bc khai bo

Chn mt Field trng trn QBE v nh v du nhy trong dng Field ri nhp vo biu thc tnh ton cn thit.

Nu biu thc di th nhn t hp phm Shift+F2 m ca s Zoom.

Nhn Enter kt thc biu thc. Access t t thm tn mc nhin vo trc biu thc v phn cch bi du 2 chm.

V d: to Field tnh ton hin th H Tn ca Bng HOCSINH Expr1:[HOLOT] & & [TENHS] - Sa li tn Field cho ph hp (phn Expr1) HOTEN: [HOLOT] & & [TENHS]

7.4.3 Hin th mt phn d kin kiu TEXT, kiu ngy

C th to mt Field tnh ton trong . S dng hm LEFT(Text,n), RIGHT(Text,n), MID(Text,n1,n2)

trch mt phn d liu kiu TEXT. S dng hm DATEPART(DatePart,Date) trch mt phn d

liu kiu ngy, trong tham s datepart l k hiu tt ch thnh phn thuc ngy (d: ngy, m: thng, yyyy: nm (4 k s), q: qu (Quarter), ww: tun (week)).

V d: tr ngy ca OrderDate l 3-Jun-93, biu thc Datepart(m,[OrderDate]) cho kt qu l 6 (thng trong nm).

7.4.4 Hin th c iu kin

S dng hm IIF() nh iu kin hin th cho Field.

C php hm: IIF(iu kin, tr ng, tr sai).

V d: To Calculated Field hin th s lng nhp bit rng trong Bng c s ch c mt Field SOLUONG ghi chung s lng nhp xut v dng MSPHIEU (k t N hay X) phn bit nhp xut. Calculated Field nh sau:

SLNHAP : IIF([MSPhieu]=N, [SOLUONG],0)

Microsoft Access

79

7.4.5 Trch chn tr duy nht Mc nhin, Query s hin th nhng Record tha tiu chun

khai bo dng Criteria. Mun ch hin th Record duy nht khi c nhiu Record tha tiu chun: khai bo thuc tnh Unique Value ca Query l YES.

7.5 QUERY TNH TNG CNG NHM

7.5.1 Kt nhm d liu

C th hin th cc mu tin trong Query theo nhm: kt nhm d liu.

Thao tc - M Query trong Design View, a cc Bng lin quan vo

Query. a cc Field lin quan vo li QBE. - Sp xp cc Field cn kt nhm theo th t t tri sang phi.

Field kt nhm cao nht c t ngoi cng bn tri li QBE.

- a dng Totals vo li QBE: chn menu VIEW Totals hay click biu tng Total trn Toolbar

- Chn mc GROUP BY trn dng Total ca Field cn kt nhm.

7.5.2 Tnh tng

C th thc hin cc php tnh Tng ttrn nhm d liu no bng cch s dng Query tng cng (Totals Query).

Trong Query ny, khai bo hin th nhng tr tng cng v Query ny cn c gi l Aggregate Query (Query tnh gp).

7.5.2.1 Cc hm c th s dng trong Query tng cng

Tn hm ngha SUM Tnh tng ca mt Field s hc AVG Tnh trung bnh ca mt Field s hc MIN/MAX Tnh tr cc i/cc tiu ca mt Field s hc COUNT m s lng mu tin c d kin trong Field FIRST/LAST Tr ca Field thuc mu tin u tin/cui cng ca

Bng/Query

7.5.2.2 Tnh tng i vi tt c Record ca Bng To Query m d liu c s l Bng/Query mun tnh tng v

a dng Totals vo lui QBE. Trong mi dng Total ca mi Field, chn php tnh (SUM,

AGV, ). V mun tnh tng ca tt c cc Record nn khng khai bo GROUP BY (Tng theo nhm).

Microsoft Access

80

Trong bng kt qu Query, Access hin th nhng tiu nhn bit Bng Query tng cng chng hn nh AvgOfUnit, SumOfPrice, v ngi s dng c th thay i li cc tiu .

7.5.3 Khai bo tiu chun la chn trong Query tng cng nhm

C th khai bo tiu chun la chn trong Query tng cng nhm v nh vy cng c ngha l gii hn mu tin tng kt c hin th thuc mi nhm. V d: To bng Query tng cng theo nhm mt hng: khai bo tiu chun cho Field mt hng (Field tnh tng l Field s lng).

Khai bo tiu chun tng cng: khai bo tiu chun cho Field lm tiu chun la chn (nhng khng l Field dng tnh tng).

Khi chy Query, Access s thc hin i vi tt c cc mu tin ca Bng la chn ri la chn cc Record theo tiu chun ch nh. Ni cch khc, tng cng trc ri mi la chn Record kt qu.

7.5.4 Khai bo tiu chun gii hn Record trc khi tng tng

Vi phng thc ny, Access thc hin vic la chn trc ri mi tnh tng cng.

Khai bo tiu chun - Phi khai bo tiu chun cho Field lm tiu chun chn loi - V khai bo tiu chun cho c Field dng tnh ton - V d nh khai bo tiu chun cho Field mt hng v khai bo

tiu chun cho Field s lng (Field tnh tng).

7.5.5 Khai bo biu thc tng cng - Mc chn Expression

Khi thit lp Query tnh tng, ti dng Total ca Field mun tnh tng, php tnh thng dng l cc hm n gin c sn. Trng hp mun t khai bo mt biu thc khc bit vi nhng mc chn tnh ton sn c ti mc Total th lm nh sau: M Query trong Design View v hin th dng Total trn QBE. dng Total ca Field mun lp biu thc, chn mc

EXPRESSION. Ti dng FIELD ca Field cn lp biu thc: nhp biu thc hay

dng cng c Expression Builder khai bo biu thc. GHI CH 9 trong 12 mc chn ca dng Total l cc hm Aggregate (hm

tnh gp). Cc hm ny khng bao gm cc Field cha tr NULL. m tr NULL, phi chuyn chng thnh zero (hm NZ()).

Cc ty chn cn li ca dng Total:

Microsoft Access

81

Chn GROUP BY nh ngha cc nhm mun thc hin tnh ton. V d:

trnh by tng s bn theo LOAIHH, chn Group By Field LOAIHH.

EXPRESSION To mt Calculated Field c nh km hm Aggregate trong biu thc ca n. Thng thng to mt Calculated Field khi mun phi hp nhiu hm trong mt biu thc.

WHERE Ch nh tiu chun cho mt Field m khng dng nh ngha nhm. Nu ch nh ty chn ny cho mt Field, Access s n n trong kt qu ca Query (b chn checkbox SHOW).

7.6 SUMMARY SELECT QUERY

7.6.1 Khi qut

- Khi c nhu cu xem kt qu tng hp m khng quan tm n cc Record chi tit: Thu Chi trong ngy (khng quan tm thu chi v vn g). y l lnh vc thch hp cho Summary Select Query.

- V d Bng PHATSINH lu cc hot ng pht sinh hng ngy gm xut nhp vt t v cc hot ng thu chi. Yu cu lp mt Query hin th s liu thu chi trong ngy (khng hin th cc l do thu chi).

7.6.2 To Summary Select Query n gin

- To mi Select Query (Design View). Chn Bng tham gia (v d Bng PHATSINH).

- Chn cc Field a vo QBE (v d Field NGAYCT, LOAICT, TIEN)

- a dng TOTAL vo li QBE. - Trn dng Totals: chn GROUP BY cho NGAYCT (v xp th

t Ascending), SUM cho TIEN v WHERE cho LOAICT. - Dng Criteria ca LOAICT nhp: T Or C (chng t l thu

hay chi)

7.6.3 Summary Select c s dng Calculated Field

Yu cu lp mt Query hin th s liu thu chi trong ngy theo hai ct ring: ct Thu v ct Chi.

- To mi Select Query (Design View). Chn Bng tham gia (PHATSINH).

- Chn cc Field a vo QBE (NGAYCT, LOAICT, TIEN). - a dng TOTAL vo li QBE

Microsoft Access

82

- Trn dng Totals: chn Group BY cho NGAYCT (v xp th t Ascending) v WHERE cho LOAICT.

- Dng Criteria ca LOAICT nhp: T Or C (chng t l thu hay chi)

- To 2 Calculated Field THU v CHI THU:SUM(IIF([LoaiCT]=T,[Tien],0)) v CHI:SUM(IIF([LoaiCT]=C,[Tien],0))

- Chn Expression trn dng Total cho 2 Calculated Field THU, CHI.

7.7 CC VN B SUNG

7.7.1 Thit k Query hiu chnh d liu c s

Khi thit k Query da trn mt hay hai Bng c quan h 1-1 th tt c cc Field khai bo trong Query u c th hiu chnh c. Nhng nu thit k Query trn c s d liu t nhiu Bng v mt s Bng c quan h 1-nhiu th vn c kh khn hn.

Khi thit k mt Query da trn d liu ca nhiu Bng, c th cp nht d liu trn Query, phi m bo rng cc Bng thuc quan h MT phi c Field lin kt l Field Primary Key hay ch mc duy nht.

7.7.1.1 Field no c th hiu chnh

Loi Query hay Field Php hiu chnh Query vi mt Bng c s Cho php Query vi d liu l nhng Bng c quan h 1-1 Cho php Query vi d liu l nhng Bng c quan h 1- nhiu

Thng thng cho php

Crosstab Query Khng Query c tnh ton tng cng Khng Query c thuc tnh Unique Value l YES Khng Union Query Khng Pass-Through Query Khng Cc Calculated Field ca Query Khng Field c thuc tnh Read-Only Khng Query c Attached Table Khng Field thuc Record b xa hay Kha bi USER khc

Khng (nhiu USERS)

Query hay Bng khng cho php thc hin tc v INSERT, REPLACE v DELETE

Khng

Microsoft Access

83

7.7.1.2 Hiu chnh trong Query c d liu 2 bng quan h 1- Phm vi hiu chnh

c hiu chnh mi Field tr Field lin kt vi d liu Bng pha quan h MT. C hai trng hp cn lu nh sau:

- C th hiu chnh d liu ca Field lin kt pha quan h MT thuc khai bo quan h khng cht (OUTER) khi tr Field lin kt khng c Record i chiu trong Bng pha nhiu.

- C th hiu chnh d liu ca Field lin kt quan h MT thuc khai bo lin kt trong c thuc tnh ton vn tham chiu vi mc chn CASCADE UPDATE RELATED FIELDS.

Thit k Query,Biu mu cho/khng hiu chnh d liu - Mun mt s Field trong biu mu khng c hiu chnh

Lp thuc tnh LOCKED ca cc Control ng vi Field l YES.

- Khng mun cho php hiu chnh bt c Field no Thuc tnh AllowEditing: Unavailable v thuc tnh DefaultEditing: Read-Only (hoc khai bo thuc tnh AllowUpdating l No Tables)

- Nu mun s dng cng c AutoLookup y Phi a cc Field thuc Bng pha quan h NHIU vo

QUERY. i vi biu mu th phi dng Field lin kt Bng pha nhiu nh mt Field cho php iu chnh.

y C th dng List Box hay Combo Box lit k nhng tr c th la chn cho mt Field no trong biu mu thun tin nhp d kin.

Microsoft Access

84

BI TP: 1. M tp tin QLCN.MDB ra v chn trang Queries, thc hin cc

truy vn sau: - Lit k MASP, TENSP, tng s sn phm thc hin nhiu

nht trong thng 9/2005. - Lit k MASP, TENSP m khng c b ph phm. - Lit k MACN, HOTEN, PX, tng tin lng (tnh bng cng