Giao Trinh Access DHGTVT

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TRNG I HC GIAO THNG VN TI

KHOA CNG NGH THNG TIN

NG TH THU HIN

THANH THY

BI GING

NHP MN H QUN TR

C S D LIU ACCESS

TRNG I HC GIAO THNG VN TI

KHOA CNG NGH THNG TIN

TS. NG TH THU HIN

Th.S THANH THY

Th.S NGUYN KIM SAO

GIO TRNH

NHP MN H QUN TR

C S D LIU

H ni, 01/2015

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MC LC

LI NI U ................................................................................................................ 5

CHNG 1: TNG QUAN V MICROSOFT ACCESS ............................................ 7

1. Gii thiu v Microsoft Office ................................................................................ 7

2. Lm vic vi Microsoft Access .............................................................................. 7

2.1 Khi ng Access ............................................................................................. 7

2.2 To mt c s d liu mi ................................................................................ 8

2.3 Lm vic vi c s d liu tn ti .............................................................. 10

CHNG 2: BNG V MI QUAN H .................................................................. 13

1. Cu trc ca mt bng .......................................................................................... 13

2. Thit k bng ......................................................................................................... 13

2.1 To bng .......................................................................................................... 13

2.2. t kho chnh ............................................................................................... 17

2.3 Thuc tnh ca trng ..................................................................................... 18

2.4 Thuc tnh ca bng ........................................................................................ 19

2.5 Cp nht d liu vo bng ............................................................................... 20

2.6 Xo v i tn bng ........................................................................................ 20

3. Thit lp quan h gia cc bng ............................................................................ 21

3.1 Mi quan h gia cc bng ............................................................................. 21

3.2 Cch to quan h ............................................................................................. 22

3.3 Chnh sa quan h ........................................................................................... 23

3.4 To cc ton vn tham chiu ........................................................................... 24

BI TP CHNG 2 .................................................................................................. 26

CHNG 3: TRUY VN ............................................................................................ 29

1. Tng quan v truy vn .......................................................................................... 29

2. Thao tc trn truy vn ........................................................................................... 30

2.1 Cc bc to mt truy vn mi ....................................................................... 30

2.2 t iu kin trong truy vn ........................................................................... 34

2.3 To trng tnh ton trong truy vn ................................................................ 35

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2.4 Thuc tnh ca trng v truy vn .................................................................. 36

2.5 Cc php ton v mt s hm trong Access ................................................... 37

3. Cc loi truy vn khc ........................................................................................... 43

3.1 Truy vn tnh tng (Totals) ............................................................................. 43

3.2 Truy vn thng s (Parameter Query) ............................................................ 45

3.3 Truy vn Crosstab ........................................................................................... 47

3.4 Truy vn to bng (Make Table Query) ......................................................... 51

3.5 Truy vn b sung (Append Query) ................................................................. 53

3.6 Truy vn xo (Delete Query) .......................................................................... 54

3.7 Truy vn chnh sa (Update Query) ............................................................... 56

BI TP CHNG 3 .................................................................................................. 59

CHNG 4: MU BIU ............................................................................................. 63

1. To mu biu bng Autoform v Wizard.............................................................. 63

1.1 To mu biu bng AutoForm ........................................................................ 63

1.2 To mu biu bng Form Wizard ................................................................... 64

2. Thit k Form ch Design ............................................................................. 66

2.1 Cc thnh phn trong mt Form ..................................................................... 66

2.2 Cc bc thit k Form ................................................................................... 68

3. Hp cng c Toolbox ............................................................................................ 73

3.1 iu khin Text box ........................................................................................ 74

3.2 iu khin Combo Box................................................................................... 75

3.3 iu khin Command Button ......................................................................... 83

3.4 Thit k dng Main Sub Form ..................................................................... 84

BI TP CHNG 4 .................................................................................................. 91

CHNG 5: BO BIU ............................................................................................. 93

1. To bo biu bng Autoreport .............................................................................. 93

2. To bo biu dng Report Wizard ........................................................................ 94

3. To bo biu dng Design View ........................................................................... 98

4. To cc nhn dng Label Wizard ....................................................................... 102

BI TP CHNG 5 ................................................................................................ 105

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CHNG 6: MACRO V MENU ............................................................................ 107

1. Macro .................................................................................................................. 107

1.1 To v s dng Macro .................................................................................. 107

1.2 Cc hnh ng Macro thng dng .............................................................. 109

1.3 Gn Macro vi cc s kin trn Form/Report .............................................. 109

1.4 Macro AutoExec ........................................................................................... 111

2. Menu Bar ............................................................................................................. 112

BI TP CHNG 6 ................................................................................................ 115

BI TP TNG HP ................................................................................................ 116

CHNG 7: LP TRNH C S D LIU TRONG MS ACCESS ...................... 131

1. Gii thiu lp trnh Visual Basic Application ..................................................... 131

2. Module ................................................................................................................ 132

2.1 Module chun (Standard Module) ................................................................ 133

2.2 Module lp (Class Module) .......................................................................... 148

2.3 Module ca form/report (Form/report Module) ............................................ 158

3. Kiu d liu, hng v bin .................................................................................. 168

3.1 Kiu d liu ................................................................................................... 168

3.2 Hng .............................................................................................................. 170

3.3 Bin ............................................................................................................... 171

4. Cc cu trc iu khin ....................................................................................... 175

4.1 Cu trc tun t ............................................................................................. 175

4.2 Cu trc r nhnh .......................................................................................... 176

4.3 Cu trc lp ................................................................................................... 179

5. Hm v th tc .................................................................................................... 182

5.1 Hm ............................................................................................................... 182

5.2 Th tc .......................................................................................................... 184

6. Cc m hnh truy cp c s d liu .................................................................... 184

6.1 Kin trc chng trnh ng dng MS Access ............................................... 184

6.2 Kin trc DAO (Data Access Objects) ......................................................... 185

6.3 Kin trc ADO (ActiveX Data Objects) ....................................................... 214

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BI TP CHNG 7 ................................................................................................ 241

TI LIU THAM KHO ........................................................................................... 242

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LI NI U

Trong s pht trin ca kinh t tri thc hin nay, khng th ph nhn vai tr ca

cng ngh thng tin. c bit lnh vc c s d liu v ang c nhiu ngi

quan tm. Rt nhiu h qun tr c s d liu c ng dng nh Foxpro, Access,

SQL Server, Informix, Oracle, Nhng n gin v thn thin hn c l h qun tr

CSDL Access, mc d n khng c nhng cng c h tr mnh nh Informix hay

Oracle, nhng n cng h tr tng i tt v mt qun l d liu va v nh, ng

thi n cng cung cp cng c cho php chng ta c th lp trnh c. Chnh v vy

m nhiu khi ta cn gi l ngn ng Access. Microsoft Access cung cp h thng

chng trnh ng dng rt mnh, gip ngi dng mau chng v d dng to lp cc

trnh ng dng t bt k ngun d liu no thng qua Query, Form, Report kt hp vi

vic s dng mt s lnh Access Basic hay cn gi l lp trnh VBA.

Microsoft Access tri qua nhiu phin bn, t phin bn Microsoft Access

u tin pht hnh vo nm 1992 n nay qua nhiu ln pht hnh vi trn 130 triu

bn. V vy c th ni rng Access l mt trong nhng chng trnh c s d liu ph

bin nht th gii. Hin nay mt s phin bn ang c s dng rng ri l Microsoft

Access 2007, Microsoft Access 2010, Microsoft Access 2013. Trong ti liu ny

chng ti dng phin bn Access 2013 minh ho.

Xut pht t thc t nhu cu hc tp ca sinh vin chuyn nghnh CNTT ni

chung v sinh vin trng H Giao Thng Vn ti ni ring. Chng ti vit cun gio

trnh bm st theo cng mn hc ca trng, phc v cho sinh vin nm th

nht theo hc mn Nhp mn h qun tr c s d liu.

Gio trnh c xy dng gm 7 chng:

Chng 1: Gii thiu cc khi nim c bn ca Microsoft Access

Chng 2: Trnh by cch to bng v cch s dng bng t chc d liu cho bi

ton.

Chng 3: Trnh by cch to v s dng truy vn tng hp, sp xp v tm kim

d liu.

Chng 4: Trnh by cch thit k v s dng mu biu t chc nhp d liu cho

mt bng, truy vn hoc cc bng c quan h vi nhau.

Chng 5: Trnh by cch s dng bo biu t chc in d liu ca mt bng, truy

vn.

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Chng 6: Gii thiu v Macro v Menu dng thit k giao din chng trnh.

Chng 7: Trnh by v lp trnh trong Access.

Trong qu trnh bin son gio trnh ny, mc d chng ti c gng ht sc

nhng khng trnh khi nhng sai st. Chng ti rt mong nhn c kin ng gp

ca c gi cun sch hon thin hn.

H ni, ngy 12 thng 01 nm 2015

Nhm tc gi

TS. ng Th Thu Hin

Th.S Thanh Thy

Th.S Nguyn Kim Sao

7

CHNG 1: TNG QUAN V MICROSOFT ACCESS

1. Gii thiu v Microsoft Office

Microsoft Access l mt thnh phn trong b Microsoft Office, l h qun tr c

s d liu trn mi trng Windows, trong c sn cc cng c hu hiu v tin li

d dng xy dng cc chng trnh cho mt s cc bi ton thng gp trong qun

l, thng k, k ton

Microsoft Access l phng tin trao i thng tin trn mng Internet v

Intranet, gip ngi dng nhanh chng to v s dng cc chng trnh ng dng trn

mng. Access khng nhng d dng lin kt cc thng tin lin quan m cn c th lm

vic vi nhiu ngun d liu khc: dBASE, Paradox, SQL trn nhiu loi my tnh:

my tnh vn phng (PC), my ch (Server) my mini v my ln (mainframe).

Access m nhn hai vai tr: phn mm trn my khch (client) hoc my ch v d

dng truy cp cc chng trnh ng dng khc nh Microsoft Word, Exel, PowerPoint.

Mi mt tp chng trnh thng c c mt ui quy nh, v d cc tp ca

Microsoft Word c ui l.doc, tp chng trnh Pascal c ui l. pas Mt tp

chng trnh do Access 2003 to ra c ui l.MDB, v do Access 2013 to ra c ui

l.ACCDB

Mt h chng trnh do Access to ra gi l mt Database (c s d liu).

Trong cc ngn ng nh C, Pascal, Foxpro,... mt h chng trnh gm cc tp

chng trnh v cc tp d liu c t chc mt cch ring bit. Nhng trong Access

2013 ton b chng trnh v d liu c cha trong mt tp duy nht c ui

.ACCDB. Nh vy thut ng h chng trnh hay c s d liu c hiu l t hp

bao gm c chng trnh v d liu. ngn gn nhiu khi ta gi chng trnh thay

cho thut ng h chng trnh. Nh vy t y khi ni n chng trnh hay h

chng trnh hay c s d liu th cng c ngha l mt h phn mm gm c

chng trnh v d liu do Access to ra.

2. Lm vic vi Microsoft Access

2.1 Khi ng Access

khi ng (chy) Microsoft Access bn phi chc chn rng Microsoft

Office (trong c thnh phn Microsoft Access) c ci t ng cch trn my

tnh.

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C nhiu cch khi ng Microsoft Access ph thuc vo h iu hnh trn my

tnh ca bn

Cch 1: Chn Start, Program, Microsoft Access

Cch 2: Chy t icon trn Desktop hoc TaskBar

Cch 3: Trong trng hp khng tm thy shortcut ca chng trnh trn Desktop

hoc trong menu start ta c th chy trc tip tp tin Msaccess trong th mc ci

t Office thng thng l C:\Program Files\Microsoft Office\Office.

thun tin cho qu trnh trnh by, di y s dng Access 2013 cho tt c cc

giao din v hng dn thc hnh.

Hnh 1.1 l giao din ca Access, gm:

- Thanh tiu

- Cc thanh cng c lnh

- Cc i tng trong c s d liu hin hnh

- Thanh trng thi

Hnh 1.1: Ca s Microsoft Access

2.2 To mt c s d liu mi

Trong Access 2013 tch hp tt c cc i tng to thnh file c ui l.accdb

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to 1 c s d liu mi ta lm nh sau:

T ca s Microsoft Access: chn menu File/ New/ Blank destop database.

Hnh 1.2: To CSDL mi

Bm nt Browse chn th mc s cha tp c s d liu cn to, trong hp

File Name, t tn c s d liu. Sau bm nt Create. Lc ny, mt CSDL mi

c to, ta c th lm vic vi cc i tng ca Access.

Hnh 1.3: Ca s chnh Database

Ca s trn hnh 1.3 c gi l ca s Database. y l mt trong nhng ca s rt

quan trng ca Access. Ca s bao gm:

H thng khi lnh ribbon vi cc thanh: Home, Insert,

Tiu Database: QLHangHoa l tn ca c s d liu

Cc i tng ca mt c s d liu trong Access gm (cc mc):

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+ Table: y l cc bng ca c s d liu

+ Query: l cc truy vn ca c s d liu

+ Form: cc form dng thit k giao din chng trnh

+ Report: Cc bo co thng k

+ Macro: cc Macro dng thc thi cc hnh ng trong CSDL.

+ Module: cha cc th tc c vit bng Access Basic.

2.3 Lm vic vi c s d liu tn ti

lm vic (xem, b sung, thc hin chng trnh) vi c s d liu trn ta c th

thc hin theo nhng cch sau:

Cch 1: M File Explorer, chn n th mc cha CSDL, bm p vo tn CSDL

m

Hnh 1.4: Ca s File Explorer

Cch 2: T ca s khi ng Access, CSDL phn Recent, bm chut chn, nu

khng, bm chut vo Open Other Files phn di

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Hnh 1.5: Ca s khi ng Access

Sau khi bm Open Other File, xut hin ca s di y

Hnh 1.6: Ca s m CSDL c sn

Bm chn Computer, bm nt Browse, s c hnh di, tm n ng dn cha

CSDL m

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Hnh 1.7: Ca s Open m CSDL

Cch 3: T ca s Microsoft Access chn menu File, Open, s xut hin nh hnh 1.7

trn

Khi m xong mt c s d liu, nu mun chn i tng no th ta bm chut vo

mc . Nh hnh trn ta ang chn i tng bng Hng mc Tables, mc ny cha

danh sch cc bng ca c s d liu QLhanghoa.

Hnh 1.8

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CHNG 2: BNG V MI QUAN H

1. Cu trc ca mt bng

- Cc bng l khi cu trc c bn nht ca mt c s d liu. Mt bng trong c s

d liu phi cha thng tin thch hp cho mt kiu c th ca thc th tc l bng l

ni cha cc thng tin v mt ch c th, chng hn nh danh sch th tn. Ta c

th c mt hay nhiu bng trong mt c s d liu.

- Cc bng trong c s d liu c cu trc ging nh cc t bng tnh. Mt bng gm

nhiu trng/ct (field) v mu tin/dng (record).

- Cc dng (mu tin, record) trong bng tng trng cho mt dng m t cc in hnh

ca cc thc th c lu tr trong bng. Trt t cc dng trong bng khng quan

trng, ta c th sp xp chng theo bt k trt t no m vn khng thay i ngha

thng tin trong bng.

- Trng l mt mc thng tin c th. Cc trng c th c cc kiu d liu khc nhau

nh: Text, Number, Date/Time, .

- Cc bng trong mt c s d liu thng c quan h vi nhau.

2. Thit k bng

2.1 To bng

Gi s ta cn to bng cho CSDL Quanlybanhang, khi to CSDL trng, ca s

Access cho mt CSDL mi nh sau:

Hnh 2.1: To CSDL mi

Trnh t to mt bng nh sau:

Bm chn thanh Create, chn 1 trong hai hnh thc sau

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- Chn Table: To bng v nhp d liu

- Chn Table Design thit lp cu trc bng trc, nhp d liu sau

a) Chn Table, ht qu nhn c ca s thit k hnh 2.2 nh sau:

Hnh 2.2: To bng

Bm chut vo Click to Add, xut hin menu nhp tn trng d liu, sau

khi hon thnh trng d liu th thc hin nhp d liu.

Hon tt, bm nt Save lu tn bng, trng hp khng lu, tn bng c

Access t mc nh l Table1.

b) Nu bm nt Table Design, ca s thit lp cu trc bng nh sau:

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Hnh 2.3: Thit lp trng cho bng

+ Phn trn gm 3 ct: Field Name, Data Type, Description dng khai bo cc

trng ca bng, mi trng khai bo trn mt dng

+ Phn di dng quy nh cc thuc tnh ca bng.

di chuyn gia hai phn ta c th dng chut hoc bm phm F6.

Ba ct ca phn trn c ngha nh sau:

- Field Name (Tn trng): l mt dy khng qu 64 k t, bao gm ch ci, ch s,

khong trng. Ni chung tn cc i tng trong Access nh tn bng, tn trng, tn

mu biu, cho php s dng du cch. Tuy nhin tn mt trng khng cho php

bt u bng du cch

- Data Type (Kiu d liu): Trong ct Data Type ta c th chn 1 kiu d liu cho

trng. C 10 kiu d liu sau:

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- Short Text K t di 255 byte

- Long Text K t di ln

- Number S nguyn, thc di: 1,2,3 hoc 8 byte

- Date /Time Ngy thng /gi di 8 byte

- Curreny Tin t di 8 byte

- AutoNumber S di 8 byte

- Yes/No Boolean 1 Bit

- OLE Object i tng nhng kt hnh nh, nh phn 1 Giga Byte

- Hyperlink K t hoc kt hp k t v s

- Attackment nh km file khc, nh l nh

-Lookup Wizard Cho php chn gi tr t bng khc

- Description (M t): gii thch cho r hn mt trng no . Vn bn m t s

c hin th khi nhp s liu cho cc trng.

c) Khai bo cc trng:

+ t tn trng

+ Chn kiu d liu

+ M t trng nu mun

+ Quy nh cc thuc tnh cho trng (field properties). V d: mun khai bo mt

trng l kiu s nguyn, ta phi khai bo trong ct Datatype l Number, nhng pha

di ti thuc tnh FieldSize chn kiu long Integer. (s c trnh by chi tit

trong cc phn sau)

d) Thay i thit k, chnh sa cu trc bng

Xo mt trng: Chn trng cn xo, bm phm Delete

Ch : xo ng thi nhiu trng ta c th dng cc phm Shift v Ctrl cng vi

nt tri chut chn cc trng cn xo, ri bm phm Delete, hoc vo th Design,

chn Delete Rows

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thay i ni dung (tn, kiu,) ca mt trng, ta ch vic dng bn phm

thc hin cc thay i cn thit.

chn thm mt trng mi ta lm nh sau: Chn trng m trng mi s

c chn vo trc, ri chn th Design, bm nt Insert Row.

Di chuyn trng: Chn trng cn di chuyn, ri ko trng ti v tr mi.

e) Lu cu trc bng

Khi chuyn sang ch Design, Access yu cu t tn bng trong hp Save

As, nhp tn vo Table Name, sau bm OK:

Hnh 2.4: Lu bng

Ch :

+ Sau khi ghi xong th Access tr li ca s thit k bng

+ ra khi ca s thit k v tr v ca s Database, ta cn ng ca s thit

k theo quy tc ca windows (bm chut ti biu tng ca ca s cn ng)

+ Khi ng ca s thit k bng Access s yu cu ghi cc thay i trn thit k

bng.

2.2. t kho chnh

+ Kho chnh l mt hay nhiu trng xc nh duy nht mt bn ghi. Mi bng trong

c s d liu nn c mt kho chnh.

+ Li ch ca kho chnh:

Access t ng to ch mc (Index) trn kho nhm tng tc truy vn v cc thao

tc khc.

Khi xem mu tin (dng bng hay mu biu), cc mu tin s c trnh by theo th t

kho chnh.

Khi nhp s liu, Access kim tra s trng nhau trn kho chnh.

Access dng kho chnh to s lin kt gia cc bng.

+ t kho chnh

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Thc hin theo trnh t sau:

- Chn cc trng lm kho chnh bng cch a chut sang bn tri tn trng, khi

chut chuyn sang mi tn mu en th bm chn trng, bm v r chut chn

nhiu trng

- Chn th Design, nhp biu tng kho Primary Key

Sau khi chn kha, s xut hin biu tng kha bn tri trng

V d: Trong hnh 2.5 chn MaKH l kho chnh.

Hnh 2.5: t kha chnh

+ t li kho chnh: t li kho chnh ta chn cc trng lm kho ri thc hin

nh trn.

+ Xo kho chnh: Chn trng kho, bm nt Primary Key.

2.3 Thuc tnh ca trng

a) Cch t gi tr cho cc thuc tnh

Hnh 2.6: t gi tr cho thuc tnh

Trong ca s thit k bng, mi khi chn kiu d liu mt trng th phn

General s th hin cc thuc tnh ca trng va chn. Mi thuc tnh nm trn mt

dng nh hnh 2.6.

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Lc u mi thuc tnh hoc b trng hoc c gi tr mc nh v d gi tr mc nh

ca thuc tnh FieldSize ca trng kiu Text l 50.

Gi tr ca thuc tnh c th g trc tip t bn phm hoc c th chn t mt danh

sch ca combo box.

b) Tng quan v cc thuc tnh

FieldSize: S k t ( di) ca trng Text hoc kiu ca trng Number

Format: Dng hin th d liu kiu s v ngy

DecimalPlaces: S ch s thp phn trong kiu number v Currency

InputMask: Quy nh khun dng nhp liu (Mt n nhp liu)

Caption: t nhn cho trng. Nhn s c hin th khi nhp liu thay v tn trng

(nhn mc nh)

Default Value: Xc nh gi tr mc nh ca trng

Validation Rule: Quy tc d liu hp l. D liu phi tho mn quy tc ny mi c

nhp.

Required: Khng chp nhn chui rng. Cn phi nhp mt d liu cho trng.

AllowZeroLength: Chp nhn chui rng trong trng Text, Memo

Indexed: To ch mc tng tc tm kim tren trng ny.

2.4 Thuc tnh ca bng

- Description: M t nhng nt chung ca bng

- Validation Rule: Access kim tra quy tc (iu kin) ny trc khi cho nhp mt

mu tin vo bng

- Validation Text: Thng bo li khi mt bn ghi vi phm quy tc.

M cc thuc tnh ca bng:

M bng trong ch Design View.

T th Design, chn Property Sheet hin cc dng thuc tnh ca bng.

a cc iu kin vo dng thuc tnh Validation Rule

a cc thng tin mun thng bo khi d liu nhp khng tho iu kin Validation

Rule

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2.5 Cp nht d liu vo bng

Khi chng ta mun thao tc nhp, sa, xo d liu vo bng th bng phi

c m (hay cn gi l ch DataSheet).

Mun vo ch ny ta lm nh sau: Trong khung Navigation Pane bn tri, bm p

chn bng mun m.

chuyn gia ch Design v Datasheet View, bm chn nt View gc tri.

Hnh 2.7: chuyn i khung nhn

- cp nhp d liu vo bng, ta m bng ch Datasheet

+ Ta c th xem, sa, b sung cc bn ghi mi trong ca s nhp liu.

+ chn Font ch, c ch thch hp, ta s dng chc vng Text Formatting trn th

Home

Hnh 2.8: Vng nh dng

- xo mt bn ghi trong bng ta chn hng ri bm phm Delete hoc nt Delete

trn th Home.

2.6 Xo v i tn bng

xo mt bng, ng bng nu bng ang m, ti Khung Navigation Pane,

chn bng mun xo, nhn phm Delete hot nt Delete.

i tn bng, ng bng nu bng ang m, ti Khung Navigation Pane,

chn bng mun sa i, nhn chut phi, chn Rename, g li tn bng.

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3. Thit lp quan h gia cc bng

3.1 Mi quan h gia cc bng

Khi to cc bng cho mt ng dng ta nn xem xt (cn nhc) mi quan h gia

chng. Nhng mi quan h ny lm cho mt c s d liu quan h c nhiu sc mnh.

C ba loi quan h gia cc bng: quan h mt - mt, quan h mt - nhiu, quan h

nhiu - nhiu.

+ Quan h mt mt (1-1): Trong quan h mt-mt, mi record (mu tin) trong bng

ny tng ng vi mt record trong bng th hai. Kiu quan h ny c cc li ch nh

sau: Li ch th nht, bn c th t cc field trong 2 bng vo mt bng, thnh bng

kt hp. Li ch th 2 l n c th lm gim thi gian cn thit m mt bng ln

bng cch t mt s ct cu bng thnh bng th 2 ring bit. Cui cng quan h

mt-mt c th h tr bo mt. Access p dng vic bo mt mc ngi s dng ngay

ti mc bng. Bi vy, nu c mt tp con ca cc trng trong bng cn bo mt, bn

t chng vo mt bng ring bit ngn cn ng dng truy xut ti mt s field no

. ng dng ca bn c th lin kt vi bng b gii hn tr v bng chnh qua mi

quan h mt-mt cho nhng ngi c php mi c th chnh sa, xo v thm

mi vo nhng Field ny.

+ Quan h mt - nhiu(1-n): Quan h mt nhiu l mi quan h trong mt record

ny tng ng vi mt hay nhiu record ca bng kia. y l loi quan h kh thng

dng. Loi quan h ny c th to thnh bc c bn cho mi quan h nhiu-nhiu.

+ Quan h nhiu - nhiu(n-n): Mi quan h nhiu nhiu ch tn ti gin tip, n c

xy dng trn mi quan h mt nhiu.

+ Tnh ton vn tham chiu:

Ta c th lm cho c s d liu ca mnh mnh m hn bng cch kt hp cht ch

tnh ton vn tham chiu, xo v cp nht theo cc mc. Cc quy tc ca tnh ton vn

tham chiu phi chc chn rng mi quan h gia cc bng l hp l. Cc quy tc ny

cn ngn nga vic thay i tnh c d liu.

Tnh ton vn tham chiu khng cho php vic thm d liu bn nhiu ca

mi quan h nu gi tr gi tr kho khng so khp vi bn mt trong quan h mt

nhiu.

Tnh ton vn tham chiu cn gip trnh tnh trng cc mu tin(record) b

m ci. Cc mu tin trong bng bn nhiu ca mi quan h khng c mu tin no

22

tng ng bn mt. khc phc iu ny ta ngn chn vic xo cc mu tin bn

mt nu vn cn c mt hay nhiu mu tin tng ng bn nhiu.

3.2 Cch to quan h

Bc 1: Kch chut ti biu tng Relationships trong th Databse Tools

hin th ca s Relationship cng vi ca s Show Table, xem hnh 2.9:

Hnh 2.9: Ca s Show Table

Tc dng ca 3 tab trn ca s:

+ Tab Table hin cc bng c trong c s d liu

+ Tab Queries hin cc truy vn c trong c s d liu

+ Tab Both hin tt c cc bng, cc truy vn c trong c s d liu

Bc 2: Chn cc bng v truy vn mun to a vo quan h. S dng cc phm Ctrl

hoc Shift chn nhiu bng hoc truy vn, sau bm nt Add. Sau khi chn xong

bm nt Close ng ca s Show Table, nh hnh 2.10.

23

Hnh 2.10: Ca s Relationships

Bc 3: Chn mt trng t bng chnh (Primary table) v ko sang trng tng ng

ca bng quan h, xut hin bng nh hnh 2.11

Hnh 2.11: Ca s to quan h

Nn chn mc Enforce Refential Intergrity sau chn tip 2 mc pha di m

bo ton vn d liu (s ni chi tit trong phn sau).

C th bm nt Join Type xc nh li kiu kt ni.

Cui cng bm chut ti Create to quan h. Khi s c ng thng ni gia hai

trng biu din quan h va to nhu hnh 2.12:

Hnh 2.12: Quan h gia cc bng

3.3 Chnh sa quan h

Xo quan h: bm chut ti ng quan h ri bm phm Delete.

24

Thay i kiu quan h, ta kch chut ti ng quan h bm chut phi chn Edit

Relationship sau chn nt Join Type, ta c hnh 2.13:

Hnh 2.13: Cc kiu quan h ca Access

La chn 1: Ch nhng bn ghi c gi tr bng nhau trn trng lin kt ca hai

bng mi c lin kt vi nhau. Thc t hay s dng kiu quan h ny.

La chn 2: Tt c nhng bn ghi ca bng chnh (l bng bt u ko chut

khi to quan h) u c lin kt to thnh bn ghi mi. Vi nhng bn ghi c gi

tr bng nhau trn trng lin kt gia hai bng s c to ra, ngoi ra cn trng

hp nhng bn ghi ca bng chnh khng c gi tr ca trng lin kt trn bng quan

h, khi bn ghi mi vn c to ra vi nhng trng ca bng quan h u c gi

tr trng.

La chn 3: Tt c nhng bn ghi ca bng quan h (bng quan h l bng ko

chut tr n sau) u c lin kt to thnh bn ghi mi. Vi nhng bn ghi c

gi tr bng nhau trn trng lin kt gia hai bng s c to ra, ngoi ra cn trng

hp nhng bn ghi ca bng quan h khng c gi tr ca trng lin kt trn bng

chnh, khi bn ghi mi vn c to ra vi nhng trng ca bng chnh u c gi

tr trng.

La chn 1 cn gi l lin kt ni, la chn 2 gi l kin kt tri (bng bn tri c

bo ton) v la chn 3 l lin kt phi (bng bn phi c bo ton). Lin kt tri v

phi c gi l lin kt ngoi.

3.4 To cc ton vn tham chiu

m bo tnh ton vn tham chiu ca cc bng chng ta chn nh sau:

Chn mc: Enforce Refential Intergrity trong ca s to quan h (hnh 2.9)

Nu tho mn cc iu kin:

+ Trng quan h ca bng chnh l kho chnh

25

+ Cc trng quan h c cng kiu d liu

+ C hai bng thuc cng c s d liu

Th Access lun m bo tnh cht sau: Mi bn ghi trong bng quan h phi c mt

bn ghi tng ng trong bng chnh. iu ny nh hng n cc php: xo trn bng

chnh v php thm trong bng quan h.

Khi chn Enforce Referntial Intergrity th c th s dng thm cc tu chn sau:

+ Cascade Update Related Fields: Khi sa gi tr trng kho trong bng chnh gi

tr tng ng ca cc bn ghi trong trng quan h s b sa theo. Khng cho php

thm vo mt bn ghi mi vo bng quan h khi gi tr ca trng quan h cha c

trong bng chnh. Trong hnh 2.9 ta khng th thm vo bng Diem mt bn ghi m

trong SBD cha tn ti trong bng DSThiSinh.

+ Cascade Delete Related Records: Khia xo mt bn ghi trong bng chnh, cc bn

ghi tng ng trong bng quan h s b xo. Trong hnh 2.12 khi mun xo mt mt

hng no trong bng Khach th cc bn ghi tng ng trong bng HoaDon cng b

xo theo.

26

BI TP CHNG 2

Bi 1: To bng Solieu trong c s d liu QUANLYDIEM c cu trc nh sau:

Tn trng Kiu d liu M t

Socongto Text S cng t

Chuho Text Tn ch h

Diachi Text a ch

Sotruoc Number (Long Interger) S in thng trc

Sosau Number (Long Interger) S in thng sau

Bi 2: qun l thu chi ca mt c quan ta lp c s d liu THUQUY, d liu

c lu tr trong bng Thuchi c cu trc nh sau:


SoHD Text S ho n

Loai yes/No Loi yes l thu, No l chi

Lydo Text L do thu, chi

Ngay Date/Time Ngy vit HD

Sotien Number (Single) S tin

NguoiTC Text Ngi thu, chi

Ghichu Text Ghi ch

Bi 3: qun l thi c ca mt trng ph thng ngi ta lp c s d liu THICU

gm cc bng sau:

Bng: Danhsach c cu trc nh sau:


SoBD Text S bo danh

Hoten Text H v tn

Lop Text Lp

Diachi Text a ch

Tongdiem Number (Single) Tng im 3 mn

27

Bng: SoBD_Phach c cu trc nh sau:


SoBD Text S bo danh

Phach1 Text Phch mn 1



Bng: Phach_Diem_1 c cu trc nh sau:


Phach Text Phch mn 1

Diem Number (Single) im mn th 1









Ghi ch: cc trng gch chn l cc trng kho ca cc bng.

Hy to quan h gia cc bng trn.

Bi 4: Trong bi ton qun l cng ty ngi ta xy dng c s d liu

QUANLYCONGTY gm cc bng sau:

Bng: Chinhanh c cu trc nh sau:


MaCN Text m chi nhnh

TenCN Text tn chi nhnh

Diachi Text a ch chi nhnh

28

Bng: Duan c cu trc nh sau:


MaDuan Text m d n

TenDuan Text tn d n

MaCN Text m chi nhnh thc hin

Bng: Nhanvien c cu trc nh sau:


MaNV Text m nhn vin

TenNV Text h tn nhn vin

Diachi Text a ch

Que Text qu qun

Ngaysinh Date/Time ngy sinh

MaCN Text chi nhnh m NV lm vic

Bng: Duan_Nhanvien c cu trc nh sau:


MaDuan Text M d n

MaNV Text m nhn vin

Ghi ch: cc trng gch chn l cc trng kho ca cc bng.

Hy to quan h gia cc bng trn.

29

CHNG 3: TRUY VN

1. Tng quan v truy vn

Truy vn (Query) l mt cng c mnh ca Access dng : tng hp, sp xp

v tm kim d liu. Query cho php thao tc trong cc bng d liu.

Truy vn thc cht l mt cu lnh SQL (Structured Query Language) c xy dng

nh cng c ca Access dng tng hp d liu t cc bng ngun.

Ta c th s dng chng ch nh ni dung cho cc Form v report. Query cn c

dng lm ngun d liu cho mt trang Web.

Cc loi truy vn

1. Truy vn chn (Select): l loi truy vn thng dng nht vi cc kh nng nh sau:

+ Chn bng, query khc lm ngun d liu.

+ Chn cc trng hin th.

+ Thm mi cc trng l kt qu thc hin cc php tnh trn cc

trng ca bng ngun.

+ a vo cc iu kin tm kim, la chn.

+ a vo cc trng dng sp xp.

Sau khi truy vn thc hin, d liu rt ra c tp hp vo mt bng kt qu gi l

Dynaset, n hot ng nh mt bng. Mi ln m truy vn, Access li to mt

Dynaset gm kt qu mi nht ca cc bng ngun.

Loi Query ny rt tin li khi ta ch mun th hin mt s field trong mt bng c rt

nhiu ct. Vic trch xut mt vi ct trong mt bng c th lm tng tc thao tc

ca query.

C th chnh sa, xo, b sung thng tin vo cc bng ngun thng qua Dynaset.

2. Paramerter Query: L truy vn thng s, cho php nhp cc gi tr vo v hin th

cc d liu tho mn iu kin.

3. Crosstab Query: Truy vn ny to cc bng tng hp vi d liu da trn bng hay

Query.

30

4. Action Query: Thay v tr v mt tp hp cc dng ging nh mt Select Query,

cc Action Query thc hin mt tc v da vo mt hay nhiu bng nh to bng mi,

thm, xo sa cc mu tin trong bng.

5. Union Query: l truy vn kt hp cc trng tng ng t hai hay nhiu bng.

6. Data-definition Query: Truy vn c xy dng t mt cu lnh SQL dng to

mi hoc thay i cu trc bng.

Chng ta s ln lt tm hiu v cc loi truy vn trn trong cc phn tip theo.

2. Thao tc trn truy vn

2.1 Cc bc to mt truy vn mi

Ta bit rng khi thc hin truy vn, ta nhn c bng tng hp gi l bng

Dynaset. N khng phi l bng nh xt trong chng 2, n khng c ghi vo

a v n s b xo ngay sau khi kt thc (ng) truy vn.

Mt truy vn to c th s dng to cc truy vn khc.

Cc bc chnh xy dng mt truy vn gm:

Bc 1: Trong ca s Database mc Queries, chn New hoc cc la chn sau:

+ Create Query in Design view: Xy dng truy vn theo cch ngi s dng t thit

k

+ Create Query by wizard: Xy dng truy vn bng cng c Wizard

Bc 2: Chn ngun d liu cho truy vn mi: cc bng, cc truy vn to t trc.

Bc 3: To lp quan h gia cc bng, truy vn ngun (nu cn).

Bc 4: Chn cc trng t cc bng, truy vn ngun a vo truy vn, mi.

Bc 5: a vo cc iu kin chn lc cc mu tin tho mn cc iu kin a

vo. Nu khng a vo cc iu kin chn lc th kt qu ca truy vn bao gm tt

c cc bn ghi t cc bng, truy vn ngun.

Bc 6: Chn cc trng dng sp xp cc mu tin trong Dynaset. Nu khng chn

trng sp xp th cc mu tin trong Dynaset c hin th theo th t nh trong cc

bng ngun.

Bc 7: Xy dng cc ct (trng) mi t cc trng c trong bng, truy vn

ngun. Gi s trng mi l tng, hiu, tch, thng ca hai trng c sn no .

31

Khi xy dng trng mi, c th s dng cc php ton, cc hm chun ca Access v

cc hm t lp bng ngn ng Access Basic.

V d: Gi s trong c s d liu Quanlyhanghoa gm nhng bng sau:

Hang(MaH, TenH, SLTon) lu tr tt c cc mt hng c trong ca hng.

HoaDon(SoHD, NgayHD, MaK) dng lu tr cc thng tin v vic bn hng.

ChitietHD(SoHD, MaH, SLban, Dongia) dng lu tr chi tit v tng mt hng

trong ho n. Mi quan h gia HoaDon v ChitietHD l mt - nhiu (1-n) thng qua

trng SoHD, gia Hang v ChitietHD l 1-n thng qua trng MaH

Cu hi: a ra thng tin v ngy bn, Tn hng v s lng hng c bn.

T 3 bng trn ta s xy dng truy vn tr li cu hi theo trnh t sau:

Bc 1: Trong ca s Database ca c s d liu Quanlyhanghoa, chn th Create,

chn mc Queries Design

Bc 2: Access m hp Show Table cho ta chn d liu ngun ca truy vn:

Hnh 3.1: Ca s Show Table

Tng t trong phn to mi quan h tc dng ca 3 tab trn ca s:

+ Tab Table hin cc bng c trong c s d liu

+ Tab Queries hin cc truy vn c trong c s d liu

32

+ Tab Both hin tt c cc bng, cc truy vn c trong c s d liu. Chn cc bng

Hang, HoaDon, ChitietHD sau bm nt Add. Ri bm Close ng ca s Show

Table (mun hin li ca s Show Table ta kch chut ti biu tng trn thanh cng

c.

Kt qu ta nhn c ca s Select Query gm 2 phn (Hnh 3.2). Phn trn hin danh

sch cc bng v truy vn ngun. Phn di gi l QBE cha cc trng ca truy vn

mi cn xy dng. di chuyn gia hai phn c th dng phm F6 hoc chut).

Hnh 3.2: Ca s thit k truy vn

Bc 3: To mi quan h gia cc bng: Nu khi to bng ta to quan h

(Relationship) gia cc bng ri th n s t ng xut hin quan h khi to truy

vn (nh Hnh 3.2). Nu khng ta phi to quan h trn ca s Query, quan h to ti

y ch c tc dng i vi truy vn ny. Khi ra khi truy vn n khng cn hiu lc

na.

Bc 4: Chn cc trng a vo truy vn, bng cch ko tn trng trong cc

bng/truy vn ngun t phn trn t xung dng Field ca phn di (hoc ch cn

nhy p chut vo trng cn hin th). Ta nhy p vo cc trng SoHD, NgayHD,

MaK, TenH, Slban, Dongia (Hnh 3.3).

33

Hnh 3.3: Ca s thit k truy vn

Bc 5: nh th t sp xp: (kt qu theo mt th t no )

Bm chut ti Sort ca trng cn sp xp

Chn chiu mun sp xp l tng dn (Ascending) hoc gim dn (Descending).

Nu mun sp theo nhiu trng th th t u tin t tri sang phi.

Trong v d ny ta sp xp theo chiu tng dn ca SoHD.

Bc 6: Ghi truy vn: Sau khi hon chnh vic thit k cn ghi cu trc ca truy

vn. Chn Save t menu File hoc bm chut ti nt ng ca s window: Access s

yu cu t tn vi ln ghi u tin.

Cc dng hin th truy vn: truy vn c th hin th theo cc dng sau:

+ Design View (dng thit k)

+ SQL View (cu lnh SQL tng ng)

+ Datasheet View (Bng kt qu ca truy vn)

Khi ang thit k truy vn bt k dng hin th no c th chuyn sang dng khc

bng cch chn menu View ri chn dng mun hin thi tng ng.

Thc hin truy vn:

- Trong ca s thit k truy vn kch chut ti biu tng: trong th Design

- Trong khung Navigation Pane bm p truy vn mun thc hin

Kt qu ca truy vn trn hnh 3.4

34

Hnh 3.4: Thc hin truy vn

Vic a iu kin vo cho truy vn v to cc trng tnh ton mi s c trnh by

trong phn tip theo.

2.2 t iu kin trong truy vn

Trong khi to truy vn, i khi ta ch cn quan tm n mt s thng tin tho

mn mt s iu kin no . V d ch hin th nhng hng c SLban>3 ta thc hin

nh sau:

+ a trc tip mt biu thc iu kin vo Criteria ca cc trng cn t

iu kin. Ti dng Criteria ca SLban ta g iu kin: >3.

Trong mt truy vn nu c nhiu iu kin ca cc trng cng vit trn dng Criteria,

th c hiu l iu kin v (c ngha l cc bn ghi phi tho mn ng thi cc iu

kin mi c hin th ra). Cn nu iu kin t dng OR th hiu l hoc.

V d: nu mun hin th nhng hng m c SLban >3 v c Dongia>5000 th ti

dng Criteria v ct SLban ta g >3, ti dng Criteria v ct Dongia g >5000.

Nu mun hin th nhng hng m c SLban >3 hoc c Dongia>5000 th ti dng

Criteria v ct SLban ta g >3, cn ti dng OR v ct Dongia g >5000.

+ Hoc c th dng ca s xy dng biu thc hoc ca s Zoom. m ca

s xy dng biu thc cho Criteria ca trng no ta bm phi chut ti Criteria

ca trng, ri chn Build. Nh hnh 3.5

35

Hnh 3.5: Ca s xy dng biu thc iu kin

Ti y ta c th thit lp biu thc iu kin bt k cho truy vn.

2.3 To trng tnh ton trong truy vn

to thm mt trng mi vo truy vn v gi tr ca trng s l kt qu tnh

ton ca mt biu thc ta lm nh sau:

- Ti ca s thit k truy vn. Chn mt cn trng, trn hng Field a vo tn

trng sau l du hai chm: ri a vo biu thc. Trong biu thc c th dng tn

cc trng, cc hng, cc php tnh, cc hm chun ca Access v cc hm t lp.

Trong v d trn ta thm trng mi: ThanhTien nh sau:

ThanhTien: [Slban]*[Dongia] nh trn hnh 3.6

36

Hnh 3.6: To trng tnh ton trong truy vn

Thc hin truy vn ta c kt qu nh hnh 3.7:

Hnh 3.7: Thc hin truy vn

2.4 Thuc tnh ca trng v truy vn

Thuc tnh ca trng:

Mi trng trong truy vn u c nhng thuc ring. m bng thuc tnh

ca trng ta chn trng (bm chut ti Field ca trng cn chn) sau chn

Properties t menu View hoc bm nt phi chut v chn Properties.

Thuc tnh ca truy vn:

m bng thuc tnh ca truy vn ta chn c truy vn (bng cch bm chut

bn ngoi QBE v ngoi cc cc bng/ truy vn ngun phn trn) sau tin hnh

nh khi m bng thuc tnh ca trng.

Sau khi m bng thuc tnh (ca trng hay truy vn) ta tin hnh chn cc gi tr

thch hp cho cc thuc tnh (nh khi t thuc tnh cho cc trng ca bng). Theo

37

mc nhin trng trong truy vn k tha cc thuc tnh trong bng/ truy vn ngun. V

vy nu khng t li cc thuc tnh cho mt trng trong truy vn th trng s c

cc thuc tnh nh trong bng/truy vn ngun.

Hin th cc trng ca truy vn:

hin th mt trng no trong kt qu truy vn ti Show ca trng ta

bm chn. Nu mun mt trng n trong bng kt qu ta bm chut ti show ca

trng b du chn

2.5 Cc php ton v mt s hm trong Access

Khi xy dng cc biu thc iu kin, ta c th s dng cc php ton sau :

a) Cc php ton s hc

Gm cc php ton sau:

K hiu Tn V d

^ Lu tha 2^3 = 8

* Nhn 2*3 = 6

/ Chia 7 / 2 = 3.5

\ Chia nguyn 7 \ 2 = 3

Mod Ly phn d 7 mod 3 = 1

+ Cng 7 + 3 = 10

- Tr 7 3 =10

b) Php ton ghp chui:

C php nh sau: chui_1 & chui_2 & . & chui_n

hoc chui_1 + chui_2 + . + chui_n

S cho mt chui mi bng cch ghp cc chui thnh phn li. Cc chui_i c th l

cc biu thc chui.

V d: Chu Vn & & An, cho chui kt qu l Chu Vn An

hoc Chu Vn + + An cng c kt qu vn l Chu Vn An

38

Ch : Php & linh hot hn php +, v php & s t ng chuyn cc ton hng t

dng s sang dng chui ri mi tin hnh ghp. Cn php + ch cho php ghp cc

ton hng dng chui.

V d: Ha Tay + 2006 s sinh li, nhng Ha Tay & 2006=Ha Tay2006

c) Cc php ton so snh

> Ln hn

>= Ln hn hoc bng

< Nh hn

39

Php ton BetweenAnd: Php ton ny dng biu th mt khong gi tr. V d

mun tm cc mt hng bn c s lng nm t 50 n 100 ta a vo Criteria

ca trng SLban iu kin sau: BETWEEN 100 AND 300

iu kin ny c th biu din bng cch khc nh sau: >=100 AND

40

Cc hm x l ngy:

Date(), cho ngy my ang dng

Now() cho kt qu l ngy v gi h thng.

Day(date): cho ngy ca thng, c gi tr t 1 n 31

month(date): cho kt qu l thng ca date

year(date): cho kt qu l nm ca date

Dateadd(i1, n, date) cho gi tr kiu ngy bng cch cng thm vo date n ngy hoc

thng hoc nm hoc qu tu theo i1.

V d: Dateadd(d,10,date()) cng thm 10 ngy so vi ngy hin ti.

DatePart(i1,date): Cho mt thnh phn l ngy hoc thng hoc nm hoc qu t

mt gi tr kiu ngy (date) tu theo i1. i1 c th nhn cc gi tr nh trn. i1

c th nhn cc gi tr sau: d ngy, m thng, q qu, yyyy- nm.

V d: Datepart(q,date()) cho qu hin ti.

Cc hm x l chui:

Len(St): cho di xu St

Trim(St): Xo cc du cch c hai u ca xu st

Left(String,n) cho chui con ca string gm n k t bn tri

Right(String,n) cho chui con ca string gm n k t bn phi

Mid(String, start, n) Cho chui con ca String bt u t v tr Start v gm n k t.

Str(number) i s sang chui.

Val(st) i xu St thnh s, nu khng tho mn th cho gi tr 0.

V d: Left(Ha Noi,2)= Ha, Right(Ha Noi,3)= Noi,

Mid(Dang Thu Hien,6,3)= Thu, Str(2006) kt qu l chui 2006.

Ucase(Str): Bin i xu Str thnh ch hoa.

Lcase(Str): Bin i xu Str thnh ch thng.

Hm iu kin:

IFF(k, bt1, bt2), hm ny s cho gi tr l bt1 nu biu thc k ng, ngc li cho

gi tr l bt2. Bn thn mi bt1,bt2 li c th l mt IFF.

41

V d: IFF(x>5,10,100), cho gi tr l 10 nu x>5, tri li (x

42

Hnh 3.9: truy vn iu kin s

3) a ra bng gm cc ct SoHD, TenH, SLban, Dongia, ThanhTien

trong ThanhTien=SLban*Dongia, v ch hin th nhng hng c SLban>10 v c

Thanhtien >10000000, sp xp theo chiu gim dn ca ThanhTien.

Hnh 3.10: truy vn nhiu iu kin

4) a ra bng gm nhng ct SoHD, NgayHD, TenK, TenH, SLban, Dongia,

ThanhTien. Ch hin th nhng mt hng c SLban>5 hoc Dongia>7000000, v sp

xp theo chiu gim dn ca Thanhtien.

43

Hnh 3.11: Truy vn nhiu iu kin khng ng thi

3. Cc loi truy vn khc

3.1 Truy vn tnh tng (Totals)

Truy vn ny cho php phn nhm cc bn ghi sau thc hin cc php tnh sau trn

tng nhm:

Sum: Tnh tng cc gi tr trn trng kiu Number

Avg: Tnh gi tr trung bnh ca trng kiu Number

Min: Tm gi tr nh nht ca trng kiu Number

Max: Tm gi tr ln nht ca trng kiu Number

Count: m s gi tr khc rng ca trng

First: Cho gi tr ca trng mu tin u tin trong nhm

Last: Cho gi tr ca trng mu tin cui cng trong nhm

Cc bc to truy vn tnh tng

1. Cch to nh truy vn n gin. Chn d liu ngun cho truy vn.

2. Chn mc Totals trong menu View. S xut hin dng Total trn QBE

3. Chn cc trng:

- Phn nhm (Group by trn Total)

- iu kin, tiu chun tham gia phn nhm v tnh tng:

+ C ch Where trn Total

+ C biu thc iu kin trn Criteria

- Tnh ton (chn mt hm t vo Total, i tn trng cho c ngha tnh ton)

- Chn th t hin th (dng Sort ca trng Group by v trng tnh ton)

44

- nh tiu chun hin th kt qu (a iu kin vo Criteria ca cc trng phn

nhm v cc trng tnh ton).

Cch thc lm vic ca truy vn tnh tng:

1. Da vo cc iu kin t trong cc trng (c gi tr where trn total) lc

ra cc mu tin tham gia phn v tnh ton.

2. Phn nhm v sp xp cc mu tin trong tng nhm theo cc trng phn nhm

(c gi tr Group by trn Total). Nhm ny l dy cc bn ghi c cng gi tr

trn cc trng phn nhm.

3. Thc hin php tnh theo tng nhm trn cc trng tnh ton (c hm Sum,

Avg,) trn Total.

4. Nu c cc iu kin trn cc trng phn nhm v tnh ton th ch cc dng

tho mn iu kin ny mi c hin th.

5. Nu dng thuc tnh Top Value ca truy vn th ch mt s dng bn trn mi

c hin th. Gi s gi tr ca Top Value l 2 th ch c 2 dng u ca mi

nhm c hin th trong bng kt qu.

V d: Cho CSDL Quanlyhanghoa nh phn trn. Hy a ra bng tng hp s

lng khch hng ti mi a ch ( y hiu a ch ca khch hng ch gm tn tnh),

ch thng k vi nhng khch hng c s in thoi (ngha l ct s in thoi khng

rng), v ch hin th cc a ch bt u bng ch H.

Ta thc hin cc bc nh sau:

1. Chn bng Khach lm ngun cho truy vn

2. Chn cc trng Diachi, Mak, Dienthoai

3. Chn mc Totals ca menu view

4. Ti trng Diachi:

- Bm chut ti hng Total v chn Group by

- G iu kin: like H* ti hng Criteria

5. Ti trng Mak: Chn Count ti hng Total v i tn l Soluongkhach

6. Ti trng Dienthoai

- Chn Where ti Total

- G Is Not Null ti Criteria

- Trng iu kin s khng c hin th trong bng kt qu.

Khi ta c ca s thit k nh hnh 3.12

45

Hnh 3.12: Truy vn tnh tng

3.2 Truy vn thng s (Parameter Query)

Cc Parameter Query c tn nh vy bi v chng yu cu nhp mt tham s

vo thi im trc khi query c th thc hin xong. Thay v, chng ta a nhng iu

kin c nh khi xy dng truy vn th ta c th a nhng iu kin ng hn ti

mi thi im chy truy vn. Tc l gi tr trong cc biu thc iu kin khng cn

nh trc m s c nhc nh vic nhp mi khi thc hin truy vn. Ta c th nhc

nh vic nhp mt hoc nhiu tham s.

Cc bc xy dng

Khi to biu thc iu kin thay cho mt gi tr c th ta a vo mt thng bo c

bao trong hai du : [ ]. Mt thng bo nh vy gi l mt thng s (tham s).

Dng thng bo s xut hin nh mt ch dn khi nhp liu thc hin truy vn.

V d minh ho

Gi s vi CSDL Quanlyhanghoa nh trn, ta mun thit k 1 truy vn, khi chy

c th nhp vo mt ngy bt k v n lit k ra ton b nhng ho n c lp trong

ngy .

Ta thc hin nh sau: To truy vn mi vi d liu ngun l bng HoaDon, ti dong

Criteria ca trng NgayHD ta a vo dng thng bo: [Ngy cn xem:], Ca s

thit k nh hnh 3.13

46

Hnh 3.13: Truy vn thng s

Khi thc hin truy vn xut hin ca s Hnh 3.14

Hnh 3.14: ca s thng s

Ta nhp ngy cn xem ri n OK, khi s hin th ton b nhng ho n lp vo

ngy va nhp.

truy vn thng s chy n nh v chnh xc hn th ngi ta khuyn co rng nn

khai bo kiu d liu cho cc thng s.

Qui nh kiu d liu cho thng s

quy nh kiu d liu cho cc thng s ta lm nh sau :

- M truy vn thng s ch Design View

- Chn mc Parameters t menu Query m ca s Query

Parameters.

- Ln lt a vo tn thng s v chn kiu d liu thch hp v n OK.

Khi ca s Query Parameters nh hnh 3.15:

47

Hnh 3.15: Khai bo kiu d liu cho thng s

3.3 Truy vn Crosstab

a) Cng dng:

- Truy vn Crosstab c dng tm lc d liu v trnh by kt qu theo dng c

ng nh mt bng tnh, vi mt hnh thc rt d c. V vy n thng c dng

to nn s liu so snh v tin on hng pht trin ca d liu.

- C 2 phn vic chnh trong truy vn Crosstab l :

+ Thc hin phn nhm v tnh ton (nh truy vn tnh tng)

+ Sau trong mi nhm ta li chia thnh cc nhm con, thc hin php ton trn mi

nhm con v trnh by kt qu theo tng ct (mi nhm con ng vi mt ct)

V d: Gi s trong bng Hang, bng ChitietHD ca CSDL Quanlyhanghoa gm

cc trng MaH, TenH, Loai, SoHD, MaH, SLban ta c th dng truy vn Crosstab

a ra bng thng k xem trong mi ho n c bao nhiu loi hng v mi loi hng

c s lng nh th no?:

SoHD Tng SL hng bn A B C

HD1 15 3 7 2

HD2 17 10 5

HD3 16 1 15

HD4 20 10 4

b) Cu trc ca truy vn:

A. Gm cc trng nh truy vn Total:

1. Cc trng phn nhm (Total: Group By)

2. Cc trng tnh ton (Total: Sum hoc Avg .)

3. Cc trng iu kin (Total: Where)

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B. Thm hai trng

1. Trng phn nhm con theo ct:

Total: Group by

Crosstab: Column Heading

2. Trng tnh ton trn cc nhm con

Total: Hm (Sum, Count, Avg.)

Crosstab: Value

Ch : Ni dung ca Crosstab i vi cc trng ca nhm A nh sau:

1. Trng iu kin: trng

2. Cc trng phn nhm v tnh ton, nu:

trng: khng hin th

Row heading: Hin th cc gi tr theo hng

c) Cch xy dng truy vn:

Bc 1: Chn cc bng/ truy vn ngun xy dng truy vn mi.

Bc 2: Chn mc Crosstab Query trong menu Query

Kt qu: Trong QBE xut hin thm hai hng l: Total v Crosstab.

Bc 3: Chn cc trng

1. Dng lm tiu chun la chn cc bn ghi:

Total: Where

Crosstab: trng

Criteria: iu kin chn

2. Phn nhm v hin th theo hng

Total: Group by

Crosstab: Row heading

Dng Sort, Criteria, Or c th dng

3. Tnh theo nhm v hin th theo hng

Total: Group by

Crosstab: Row heading

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Dng Sort, Criteria, Or c th dng

4. Mt trng dng phn nhm con v hin th theo ct

Total: Group by

Crosstab: Column Heading

5. Mt trng dng tnh ton trn cc nhm con v hin th kt qu theo bng

Total: Hm (Sum, Count, Avg, )

Crosstab :Value

Bc 4: Ghi v t tn cho truy vn.

V d 1: Gi s c bng Hang, ChitietHD ca CSDL Quanlyhanghoa gm cc

trng MaH, TenH, Loai, SoHD, MaH, SLban. Hy a ra bng thng k trn.

Cc bc thc hin:

1. Chn bng Hang, ChitietHD lm d liu ngun

2. Chn kiu truy vn Crosstab

3. a vo truy vn cc trng sau:

- Trng phn nhm l: SoDH

- Trng tnh ton trn nhm l SLban ( tinh tng s lng hng bn ca mi ho

n).

- Trng phn nhm con l trng Loai (mi loi thng k xem c s lng bn nh

th no?)

- Trng tnh ton trn nhm con l trng SLban( tnh tng s lng hng bn ca

mi loi)

Mn hnh thit k nh hnh 3.16

50

Hnh 3.16: Truy vn Crosstab

Bc 4: Ghi li thit k truy vn v chy khi ta c kt qu nh hnh 2.17

Hnh 3.17: Kt qu truy vn Crosstab

V d 2: gi s c bng HOCSINH (KHOI, LOP, TO, LOAI, HOTEN)

Yu cu t ra l xy dng bng tng hp theo mu nh sau, ch thng k vi khi 9.

Lp T S s Km t Kh Gii

9A 1 10 1 4 2 3

9A 2 12 5 5 2

9A 1 9 2 7

9B 2 14 5 4 1

Trong v d ny chng ta c cc trng phn nhm, l LOP, TO v trng LOAI s

l phn nhm nh hin th theo ct.

Cc bc lm nh sau:

1. Chn bng HOCSINH lm ngun cho truy vn

2. Chn kiu truy vn Crosstab

3. a vo truy vn cc trng sau:

- Trng iu kin l trng KHOI

- Cc trng phn nhm l: LOP v TO

- Trng tnh ton ( tnh s s theo t) l trng HOTEN

- Trng phn nhm con l trng LOAI (mi t thng k xem c bao nhiu hc sinh

gii, kh, trung bnh).

- Trng tnh ton trn nhm con l trng HOTEN (m s hc sinh tng loi).

Ca s thit k truy vn c dng hnh 3.18:

51

Hnh 3.18: Truy vn tnh tng

3.4 Truy vn to bng (Make Table Query)

Cng dng:

Truy vn ny cho php to ra mt bng mi da trn bng ngun c cung cp.

Khi thc hin truy vn, kt qu ca truy vn c ghi ra a di dng mt bng mi.

Cc bc xy dng:

Bc 1. Tin hnh thit k nh i vi mt truy vn chn thng thng.

Bc 2. Sau chn th Design, chn nt Make Table

Access s yu cu dt tn cho bng mi cn to nh hnh 3.19

Hnh 3.19: Truy vn to bng

Ti y ta c th xc nh bng mi cn to nm trong CSDL hin ti hoc c th nm

trong CSDL khc, khi ta bm chn Another Database v a vo tn file CSDL

.

52

Bc 3. t tn bng vo Table Name v chn OK tr v ca s thit k truy

vn.

Bc 4. Ghi truy vn v thc hin truy vn nhn bng mi.

Ch : Do tnh nguy him ca truy vn hnh ng nn khi thc hin mt truy vn hnh

ng Access s ra thng bo yu cu s khng nh. Ni dung ca thng bo trong

truy vn to bng nh sau:

Hnh 3.20: Xc nhn truy vn to bng

V d: Gi s ta c CSDL Quanlyhanghoa gm 2 bng:

HoaDon (SoHD, NgayHD, MaK), ChitietHD (SoHD, MaH, SLban, Dongia)

Hy xy dng truy vn to mt bng mi c tn l [HoaDonCu], dng lu nhng

ho n bn hng trc ngy 12/12/2011.

Cc bc thc hin nh sau:

Bc 1: To nh truy vn thng thng, bng d liu ngun l HoaDon, ChitietHD.

iu kin ti trng NgayHD l:

53

3.5 Truy vn b sung (Append Query)

Cng dng:

B sung d liu t mt bng/ truy vn vo cui mt bng c.

Cc bc xy dng:

Bc 1: Tin hnh nh i vi mt truy vn chn thng thng.

Bc 2: Chn th Design, chn nt Append . Access s yu cu nhp tn bng cn

b sung d liu (bng cn phi tn ti).

Bc 3: Nhp tn bng cn b sung d liu.

Bc 4: Trong hng Field: a cc trng ca bng/truy vn ngun.

Bc 5: Trong hng Append to: a cc trng tng ng ca bng nhn (bng cn

b sung d liu).

Ch : Nu bng/truy vn ngun c cng cu trc nh bng nhn (cng s trng, th

t, tn v kiu) th c th ko du * ca bng/truy vn ngun vo hng Field. Nu bng

nhn khng c cc trng nh bng ngun th cc trng t ng c b qua

khi ta chn du *.

V d: Gi s trong CSDL Quanlyhanghoa c bng:

Khach(MaK,TenK,Diachi,Dienthoai), v cng c mt bng KhachHCM c cu trc

ging nh bng Khach nhng cha tt c nhng khch hng c a ch pha nam.

By gi cn b sung ton b nhng khch hng trong bng KhachHCM vo cui ca

bng Khach. Ta thc hin nh sau:

Bc 1: To mt truy vn thng thng vi d liu ngun l bng KhachHCM (l

bng ly d liu ra b sung)

Bc 2: Chn th Design, nhn nt Append , ta c c nh hnh 3.22

54

Hnh 3.22: Truy vn b sung

Bc 3: Trong hp Table Name, ta a vo tn bng Khach (l bng s c d liu

b sung vo) ri bm OK. Kt qu s xut hin thm dng Append to trong vng QBE

Bc 4: Ko du * ca bng ngun (KhachHCM) vo 1 ca hng field. Kt qu

- Trong c ko xung hin ni dung: KhachHCM.*

- Trong trng ng trn hng Append to xut hin ni dung: Khach.*

Ca s thit k nh hnh 3.23

Hnh 3.23: B sung bng

Bc 5: Ghi v thc hin truy vn, ta s thy ton b phn d liu ca bng

KhachHCM c b sung vo cui bng Khach.

3.6 Truy vn xo (Delete Query)

Cng dng: Xo cc mu tin t bng ngun. Ta nn thn trng khi thc hin truy vn

Cch xy dng:

Bc 1: Chn cc bng/truy vn ngun.

Bc 2: Chn th Design, bm nt Delete . Kt qu s hin thm hng Delete

trong na di ca ca s thit k truy vn.

Bc 3: Ko du * ca bng mun xo vo Field. Khi t From xut hin ti

tng ng trn dng Delete.

Ch : Ch c xo cc bn ghi mt bng trong s cc bng ngun.

Bc 4: Ko cc trng dng lp iu kin vo dng Field. T Where xut hin

trn dng Delete.

55

Ch : C th s dng trng biu thc lp iu kin. Khi cn ko thm mt s

trng dng to ra trng biu thc.

Bc 5: Ghi v thc hin truy vn.

V d:

Gi s trong CSDL Quanlyhanghoa c bng:

ChitietHD(SoHD,MaH,SLban,Dongia). Ta cn xo b nhng bn ghi trn bng ny

m c Thanhtien=SLban*Dongia

56

3.7 Truy vn chnh sa (Update Query)

Cng dng: Cho php chnh sa d liu trong mt hay nhiu bng.

Cch xy dng:

Bc 1: Chn cc bng/truy vn ngun.

Bc 2: Chn th Design, bm nt Update . Kt qu hin thm hng Update to

trong phn QBE.

Bc 3: Ko cc trng cn sa v cc trng dng thit lp iu kin vo hng

Field. Cng mt trng c th va l trng cn sa va l trng t iu kin.

Bc 4: t cc biu thc vo Update To ca cc trng cn sa. Gi tr ca biu

thc s l gi tr mi ca cc trng ny. Trong biu thc c th s dng cc trng

ca bng/ truy vn ngun, cc hm chun ca Access v cc hm t lp.

Bc 5: t cc biu thc iu kin vo cc Criteria ca cc trng iu kin.

Bc 6: Ghi v thc hin truy vn.

V d 1:

Gi s trong CSDL Quanlyhanghoa c bng:

ChitietHD(SoHD,MaH,SLban,Dongia). Gi s v mt l do no , cn gim

5%Dongia cho nhng mt hng c Slban

57

Hnh 3.25: Truy vn chnh sa

Bc 6: Ghi v thc hin truy vn ta thy gi ca nhng mt hng trong bng

ChitietHD c thay i nu n c SLbn ti mi ln

58

Hnh 3.26: Truy vn chnh sa

Bc 5: Ghi v thc hin truy vn ta thy gi ca c hai bng u c s thay i.

V d 3:

Gi s trong CSDL QuanlySinhvien c bng

Danhsach(MaSV, Hoten, Ngaysinh, Que, DTB, Hocbong)

C 2 mc hc bng cho sinh vin l loi A=350.000 cho cc sinh vin c im trung

bnh t t 8.0 tr ln. Loi B= 250.000 cho cc sinh vin c im trung bnh thuc

vo on m [7.0,8.0). cp nht d liu cho trng Hocbong, ta xy dng truy vn

nh sau:

Bc 1: Chn bng Danhsach lm d liu ngun.

Bc 2: Chn th Design, bm chn nt Update. Kt qu hin thm hng Update to

trong phn QBE.

Bc 3: Ko trng Hocbong vo hng Field.

Bc 4: Trong Update To ca trng Hocbong a vo biu thc sau:

IIF([DTB]>=8.0,350.000,IIF(([DTB]>=7.0) and ([DTB]

59

BI TP CHNG 3

Bi 1: S dng c s d liu QUANLYDIEM trong phn bi tp chng 2 xy dng

truy vn hin tt c d liu c trong bng Solieu.

Bi 2: S dng c s d liu THICU trong phn bi tp chng 2. Thit k truy vn

hin cc thng tin: S bo danh, H tn, a ch, im trung bnh 3 mn ca tt c cc

th sinh.

Bi 3: Da trn c s d liu QUANLYCONGTY trong phn bi tp chng 2, thit

k truy vn hin th cc thng tin H tn, a ch, cc d n, tn chi nhnh ca mt

nhn vin trong cng ty khi bit m nhn vin.

Bi 4: Hy lp bng bo co nh sau:

Loi ho n Gi tr

Yes 300.000

No 423.000

Da trn bng Thuchi ca c s d liu THUQUY trong phn bi tp chng 2.

Bi 5: Lp bng tng hp nh sau:

D n chi nhnh 1 chi nhnh 2 . Chi nhnh n

D n A 3 2 2

D n B 4 0 4

D n C 1 1 1

Da trn cc bng trong c s d liu QUANLYCONGTY trong phn bi tp chng

2.

Bi 6: Cho CSDL Quanlyvattu gm cc bng sau:

VATTU(mavattu, tenvattu, donvitinh, dongia, chungloai)

KHACH(makhach,tenkh, diachikh, dienthoai)

KHO(makho, diachikho)

PHIEUNHAP(sophieu, ngaynhap, makhach, makho)

60

DONGVATTU(sophieu, mavattu, soluong).

Hy xy dng truy vn tr li cc yu cu sau:

1. Xy dng truy vn t tn l TV1 gm nhng trng Sophieu, ngaynhap,

tenkhach, makho, diachikho, tenvattu, soluong, dongia,

Thanhtien(=soluong*dongia).

2. Xy dng truy vn t tn l TV2 ly d liu ngun l TV1 v ch hin th

nhng trng sau: Sophieu, ngaynhap, tenkhach, tenvattu, soluong,

dongia,Thanhtien. Yu cu ch hin th nhng phiu nhp vo 05/2005 v c

soluong>100, sp xp theo chiu gim dn ca sophieu.

3. Xy dng truy vn thng s t tn l TV3, cho bit mt ngy bt k c nhng

phiu nhp no c lp.

4. Xy dng truy vn tnh tng t tn l TV4, a ra bng thng k s lng

khch ti mi a ch nh sau: V ch hin th nhng a ch c s khch >2.

a ch S lng khch

5. Xy dng truy vn Crosstab t tn l TV5, a ra bng thng k v chng loi

vt t nh sau:

S phiu Tng SL vt t Chng loi 1 Chng loi 2 Chng loi 3

N100 20 10 4 6

N200 10 0 7 3

6. Xy dng truy vn to bng c tn l TV6, dng to ra bng c tn l

TONGHOP c d liu l ton b TV1 vi nhng bn ghi c Thanhtien>50000.

7. Gi s c bng PHIEUNHAP2 c cu trc nh bng PHIEUNHAP. Xy dng

truy vn b sung c tn l TV7, dng b sung d liu trong bng

PHIEUNHAP2 vo cui ca bng PHIEUNHAP.

8. Xy dng truy vn xo c tn l TV8, dng xo nhng phiu nhp c ngy

nhp trc 1/1/2000 trong bng PHIEUNHAP.

9. Xy dng truy vn sa c tn l TV9, dng tng n gi ca vt t ln

10%Dongia c trong bng VATTU.

Bi 7: Cho CSDL SINHVIEN nh sau:

Bng HOSO lu h s cc sinh vin gm cc trng:

- MaSV: Text, rng 10, kho chnh, lu m sinh vin.

61

- Ho: Text, rng 15, lu phn h v tn m ca SV.

- Ten: Text, rng 6, lu phn tn ca SV.

- NgaySinh:Date/Time, lu ngy sinh

- GioiTinh:Text, rng 3, lu gii tnh l Nam hay Nu

- Khoa: Text, rng 20, tn khoa sinh vin hc.

- QueQuan: Text, rng 50, ghi qun qun ca SV gm huyn v tnh.

- DiaChi:Text, rng 50, a ch c tr hin ti ca SV

- Dienthoai: Text, rng 12, in thoi ca SV nu c

- Giaitich, Daiso, Tinhoc, Triethoc, Anhvan: Number, Double, lu im thi cc

mn hc k I nm th nht ca SV.

Bng GIADINH lu nhng thng tin ngi thn trong gia nh c trch nhim trc

tip i vi SV gm cc trng:

- MaSV:Text, rng 10, m sinh vin, dng lin kt vi bng HOSO.

- Hoten: Yext, rng 25, lu h v tn ngi thn ca SV

- Namsinh: Number, long Integer, lu nm sinh.

- Quanhe: Text, rng 12, quan h vi SV.

- Diachi: Text, rng 50.

- Dienthoai: Text, rng 12, s in thoi lin h nu c.

Mi quan h gia bng HOSO v bng GIADINH l 1-n thng qua trng MaSV.

To cc truy vn sau:

1. Query 1: d liu ngun l bng HOSO to mt truy vn hin th cc trng

MaSV, Ho, Ten, Khoa, GiaiTich, DaiSo, TinHoc, Triethoc, Anhvan, DiemTB(bng

im trung bnh ca c 5 mn hc). Danh sch sp xp theo theo hai trng: Khoa

tng dn, v DiemTB gim dn.

2. Query 2: Dng truy vn Make Table to mt bng mi KhoCNTT gm tt c cc

trng ca bng HOSO nhng ch gi li cc SV thuc khoa CNTT

3. Query 3: T hai bng HOSO v GIADINH a ra bng d liu gm cc ct MaSV,

H tn sinh vin, H tn ngi thn trong gia nh, Quan h ngi thn vi SV. Danh

sch sp xp theo chiu tng dn ca Tn SV.

4. Query 4: T bng HOSO a ra danh sch c SV phai thi li (mt trong cc mn

di 5 im) gm cc ct: MaSV, Ho, Ten, Khoa, Giaitich, Daiso, Tinhoc, Trithoc,

Anhvan. Danh sch sp xp theo chiu tng dn ca trng Ten.

62

5. Query 5: dng truy vn thng s a ra danh sach cc SV c cng tui(tui nhp

vo t bn phm) gm cc trng: MaSV, Ho, Ten, Ngaysinh, GioiTinh, Khoa.

63

CHNG 4: MU BIU

Mu biu (Form) dng hin th v cp nht d liu. T chc giao din

chng trnh. Ngi ta ni rng Form chnh l b mt ca cc ng dng, bi giao

din ngi dng ca mt ng dng hu nh u thng qua cc Form, nn vic thit k

v thao tc Form l rt quan trng.

Mu biu gm cc iu khin thuc cc th loi khc nhau v c cng dng

khc nhau. Chng hn iu khin Label (Nhn) dng th hin cc dng vn bn,

iu khin Text Box (hp vn bn) dng th hin gi tr cc trng, cc biu thc

hoc gi tr g t bn phm.

Access lun cho php kt hp form v d liu mt cch d dng v n gin.

y l mt trong nhng l do chnh ti sao n l mi trng pht trin ng dng

nhanh.

Ngun d liu (nu c) ca mu biu l mt bng hoc mt truy vn. Khi c

ngun d liu, mu biu dng th hin v cp nht d liu cho cc trng ngun.

Mu biu khng c ngun d liu (Unbound) thng dng t chc giao din

chng trnh.

1. To mu biu bng Autoform v Wizard

Nu ch dng biu mu th hin v cp nht d liu th cch nhanh nht l

dng cch to t ng hoc bng Wizard.

1.1 To mu biu bng AutoForm

AutoForm gip chng ta t ng to c mt Form nhanh chng biu hin

th thng tin t mt bng/ truy vn trong c s d liu.

Trong ca s Database chn th Creat, trong mc Forms. Xem hnh 4.1

Hnh 4.1: Vng nt lnh to Form

Nt Form dng to mu biu mi t ng.

Nt Form Design dng m ca s thit k mu biu

64

Nt Blank Form dng to mu biu trng.

Nt Form Wizard to mu biu tng bc

to mu biu bng Auto Form, thc hin cc bc:

Bc 1: Bm chn bng hoc truy vn cn to Form

Bc 2: Bm nt Form, Access s to Form v t ng a cc bng c lin kt vi

bng va chn vo Form

Hnh 4.2: Form c to t Auto Form

Bc 5: t tn cho mu biu

1.2 To mu biu bng Form Wizard

To Form bng Wizard l to Form bng cch lm theo tng bc do Access qui nh

sn. Cc bc thc hin nh sau:

Bc 1: Chn th Create, bm chn nt Form Wizard . Ca s Form

Wizard xut hin nh hnh 4.3.

65

Hnh 4.3: Ca s Form Wizard

Bc 2: Chn bng lm d liu ngun cho Form (trong v d ny chn bng Khach).

Chn cc trng mun a vo mu biu ti ct Available Field, ri bm vo nt >

a sang ct Selected Fields. Nu mun a sang tt c cc trng ta bm nt >>. Nu

mun b trng no chn trong ct Select Field th ta bm

66

Hnh 4.5: Form c to t Form Wizard

Nhn xt: Sau khi s dng Auto hoc Wizard ta c th m Form ch Design

c th thit k thm theo mnh.

2. Thit k Form ch Design

2.1 Cc thnh phn trong mt Form

Form (mu biu) gm 5 thnh phn:

u biu (Form Header)

u trang (Page Header)

Thn (Detail)

Cui trang (Page Footer)

Cui biu (Form Footer)

Xem hnh 4.6 ta s thy c cc thnh phn ca Form:

67

Hnh 4.6: Cc thnh phn ca Form

hin(n) cc thnh phn u/ cui biu hoc u/ cui trang,

bm chut phi trn Form, chn Form Header/Footer hoc Page

Header/Footer.

ngha:

- u biu, Cui biu (Form Header / Foom Footer):

+ Dng trnh by tiu , hng dn s dng cc nt lnh

+ C th khng in u biu bng cch t gi tr Screen Only vo

thuc tnh Display when1

+ C th khng cho hin th u biu (khi thc hin Form) bng thuc tnh: Visible:

No

- u trang, cui trang (Page Header, Page Footer): ch xut hin khi in

Thn biu (Detail): Cha cc iu khin buc vo cc trng ngun.

Thuc tnh ca mu biu v cc thnh phn ca n:

Tng thnh phn (trong 5 thnh phn ca mu biu) c bng thuc tnh ring. Mu

biu cng c bng thuc tnh. Mun m bng thuc tnh ca i tng no ta lm nh

sau:

+ u tin chn i tng cn m bng thuc tnh

68

+ Sau : hoc chn Properties trong menu View hoc bm nt phi chut chn

Properties.

2.2 Cc bc thit k Form

2.2.1. Cc bc thit k

Bc 1: Chn th Create, bm nt Form Design.

Bc 2: Chn th Design, bm nt Add Existing Fields nhp d liu ngun

cho Form.

Bc 3: Thit k ni dung ca Form nh hp cng c. Ti y ta c th a vo Form

nhng iu khin, cn chnh, trang tr Form,

Bc 4: Ghi v t tn cho Form.

Cc loi iu khin thng dng

Hp cn bn (Text Box): Dng nhp v hin th d liu

Nhn (Label): Dng vit tiu ca Form v ca cc hp vn bn

Hp la chn (Combo box): Dng la chn d liu c sn

Hp danh sch (List Box): Dng chn d lliu c sn trong mt danh sch

Nt lnh (Command Button): Dng thc thi mt lnh no

Nhm la chn (Option Group): Th hin mt nhm cc la chn

Cch dng cc iu khin:

+ Bound: iu khin buc vo mt trng, dng truy xut ti trng

+ Unbound: iu khin khng buc, khng lin quan n trng no c, dng :

Nhp d liu t bn phm, Trnh by tiu , trang tr hnh v, hp ng

+ Calculated: iu khin tnh ton, dng th hin gi tr ca mt biu thc

Cch to mt iu khin

- Chn loi diu khin: Bm vo nt tng ng trn hp cng c.

- Di chuyn n v tr cn t iu khin vo biu mu v bm chut.

- Thc hin cc sa i cn thit.

2.2.2. Chn ng thi cc iu khin

C th chn ng thi cc iu khin theo cc cch sau:

69

+ Kt hp gia phm Shift v chut

+ Bm chut ti mt v tr trn thc dc mp tri mu biu chn cc iu khin

trn cng mt hng cha v tr bm.

+ Bm chut mt v tr trn thc ngang (mp trn biu mu) chn cc iu khin

trn cng mt ct cha v tr bm.

+ C th dng phm Shift v cch bm trn thc chn ng thi cc iu khin

nm trn nhiu hng, nhiu ct.

+ chn cc iu khin nm trn cc hng lin tip, ta di chut ti hng u ti

thc dc, ri ko chut theo thc ti hng cui.

+ chn cc iu khin nm trn cc ct lin tip, ta di chut ti ct u ti thc

ngang, ri ko chut theo thc ti ct cui.

2.2.3. Thuc tnh ca iu khin

m bng thuc tnh ca mt iu khin ta lm nh sau: Chn iu khin cn m

bng thuc tnh. Chn View/Properties, hoc bm p chut ti iu khin, hoc bm

nt phi chut ri chn Properties. Bng thuc tnh c dng sau:

70

Hnh 4.7: Bng thuc tnh

Mi loi iu khin c th c mt s thuc tnh khc nhau. Ti y trnh by mt s

thuc tnh hay dng.

Name: tn iu khin

Caption: tiu

Control Source: ngun d liu

Format: quy nh hnh thc hin th

Default Value: gi tr mc nh

Validation Value: quy tc d liu hp l

Validation Text: vn bn hp l

Input Mask: mt n nhp liu

Status Bar Text: hng dn s dng iu khin (hng dn ny s hin ti dng trng

thi)

di chuyn cc / nhm iu khin ta chn / nhm cn di chuyn, sau ko n

v tr mi.

2.2.4. nh v cc iu khin

C th nh v cc theo cc kh nng sau:

+ Ging thng theo mp tri ca iu khin ng bn tri nht (cn tri)

+ Ging thng theo mp phi ca iu khin ng bn phi nht (cn phi)

+ Ging thng theo mp trn ca iu khin ng bn trn nht (cn trn)

+ Ging thng theo mp di ca iu khin ng bn di nht (cn di)

Thao tc nh sau:

Chn cc iu khin cn nh v, chn Form/Align v chn:

+ Left cn tri

+ Right cn phi

+ Top cn trn

+ Bottom cn di

Cch u cc iu khin

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+ Cch u theo hng: Chn Format/ Horizontal Spacing/ Make Equal

Kt qu cc u hng v cui hng khng thay i v tr. Cc khc c dch

chuyn sao cho khong cch gia hai trong hng bng nhau.

+ Cch u theo ct: Chn Format/Vertical Spacing/ Make Equal

Kt qu cc u ct v cui ct khng thay i v tr. Cc khc c dch chuyn

sao cho khong cch gia hai trong ct bng nhau.

+ Tng, gim khong cch gia cc iu khin trong hng:

Chn Format, Horizontal Spacing

Sau chn Increase tng hoc chn Decrease gim.

2.2.5. Thay i kch thc iu khin

Chn cc cn thay i kch thc. Chn Format/Size

- To Fit: cc s c kch thc va th hin ni dung trong n.

- To Tallest: cc s c chiu cao bng chiu cao ca cao nht.

- To Shortest: cc s c chiu cao bng chiu cao ca thp nht.

- To Widest: cc s c chiu rng bng chiu rng ca rng nht.

- To Narrowest: cc s c chiu rng bng chiu rng ca hp nht.

Ta c thay i Font v c ch cho mt nhm iu khin bng cch chn nhng Font

ch, c ch cn thay i.

2.2.6 Thuc tnh ca Form

Trong ch Design View nhy chut vo nt

chn Form( vung gc bn tri ca Form), sau

chn View/Properties. Hoc c th nhy p

chut vo nt chn Form. Sau s hin th hp

thoi Form, chn All, hp thoi hin tt c 107

thuc tnh ca Form nh sau:

Sau y l mt s thuc tnh hay s dng:

- Record Source: la chn bng/truy vn ngun

(bng/truy vn c cc trng cn t ln Form).

72

- Default View: la chn mt trong cc cch th hin ca Form

- Scroll Bars: Bt/ tt cc thanh cun Form

- Record Selections: Bt/ tt cng c chn bn ghi pha tri Form

- Navigation Buttons: Bt/ tt cc nt di chuyn v thm bn ghi pha di Form

- Dividing Lines: Bt/ tt cc ng li ngn cch cc thnh phn ca Form

- Control Box: Bt/ tt cc nt Min, Max, Close iu khin trn Form.

V d: Gi s to Form nhp d liu vo bng Khach trong CSDL

Quanlyhanghoa.

Bc 1: Chn th Create, bm nt Form Design. Xut hin Form trng

Bc 2: Bm chut phi trn Form, chn Form Header/ Footer hin th u Form

v cui Form. Page Header/ Footer hin th u trang v cui trang

Bc 3: Chn th Design, bm nt Add Existing Fields nhp d liu ngun

cho Form.

Ti khung Field List, bm chn Show all Table

Hnh 4.8: La chn d liu ngun

Chn bng Khch

Hnh 4.9: Bng danh sch cc bng

Bc 4: Ln lt a cc trng vo Form, bng cch ko tn trng t danh sch cc

trng vo Form. Mi trng a vo Form s to nn hai iu khin lin kt nhau:

iu khin bn phi l mt Text Box (ti v tr ny s hin th d liu ca trng ng

73

vi mt bn ghi), iu khin th hai l mt Label-nhn (Access mc nh ly tn

trng lm nhn, ta c th thay i thn thin hn).

- Ko cc trng Mak, TenK, Diachi, DienThoai vo Form

- Nhy vo nt Label trn hp Toolbox, khoanh vng ch nht trn di Form Header

xc nh mt nhn v nhp xu k t NHP KHCH HNG.

- Tng t trong di Page Header to mt nhn TRUNG TM HNG HA GIA

NH. Ca s thit k nh hnh 4.10

Bc 5: Ghi thit k Form: bm File/Save hoc bm vo nt ng ca s

Hnh 4.10: Thit k Form

3. Hp cng c Toolbox

Hp cng c l phng tin chnh xy dng cc mu biu. Mi nt trn hp cng

c ng vi mt loi iu khin v dng to cc iu khin thuc loi tng ng.

Hnh 4.11: Hp cng c Toolbox

Hp cng c c cc nt nh sau:

Select Objects (dng la chn cc iu khin trn vng ch nht), Control Wizard,

Label(to nhn), Text Box, Option Group, Toggle Button, Check Box, List Box,

Command Button, Image(to i tng hnh nh), Unbound Object Frame, Bound

Object Frame, Page Break(to ngt trang), Tab Cotrl, Subform/SubReport, Line(to

74

ng thng), Rectangle (to khung ch nht), More Controls(lit k nhiu loi iu

khin khc c th to).

Sau y chng ta trnh by mt s iu khin thng dng:

3.1 iu khin Text box

iu khin Text box dng :

- Hin th d liu ca cc trng kiu vn bn, s, v kiu memo. Cng c th dng

nhp d liu t bn phm vo.

- Dng to mt trng tnh ton trn Form:

V d: Trong Form nhp d liu cho bng ChitietHD ca CSDL Quanlyhanghoa c

dng nh hnh 4.12. C nt SLban, Dongia l mt Text box, SoHD, MaH l mt

Combo box, Thanhtien l trng tnh ton.

Hnh 4.12: Thit k Form

- Cch Text box SLban. Ko trng SLban t Field List t ln Form, my t ng

to mt Text Box c tn l SLban v thuc tnh ngun d liu Control Source l

SLban, nhn lin kt vi Text box ny c thuc tnh Caption l SLban.

- Cng tng t ta to c Text Box Dongia.

- To Text Box ThanhTien:

Nhy nt Text Box trn thanh Toolbox, nhy v ko trn Form xc nh vng ch

nht dng lm Text Box.

75

Trn th Design, bm nt Property Sheet hin thuc tnh ca Text Box hoc

nhy trc tip vo ny nhp cc thuc tnh sau:

Control Source: = [SLban]*[Dongia]

Name: ThanhTien.

M thuc tnh ca Label lin kt vi Text Box, dng thuc tnh Caption nhp Thnh

Tin, hoc nhy chut g trc tip ti Label.

3.2 iu khin Combo Box

Combo Box v List Box c th dng to danh sch la chn cho mt trng

bt k. Danh sch trong List Box lun c th hin, cn trong Combo Box ch c

m khi kch chut ti nt mi tn bn phi.

Mi mt Combo Box u phi c mt ngun d liu xy dng bng chn. Ngun

d c th l:

1. Cc bn ghi ca mt bng/ truy vn

2. Dy cc gi tr a vo khi to Combo Box (value list)

3. Tn cc trng ca bng/ truy vn (field list)

4. Cc bn ghi ca mt truy vn to bi cu lnh SELECT

5. Danh sch to t kt qu tr v ca mt hm trong Access Basic.

Tng ng ta xt ba kiu Combo Box thng dng l:

- Combo Box c gi tr ly t cc trng ca mt bng (v d nh Combo MaH ly d

liu t trng MaH ca bng Hang trong VD trn)

- Combo Box c gi tr g vo.

- Combo Box tm kim.

Khi to Combo Box ta c th dng Wizard hoc khng, sau y s trnh by hai cch

to ny.

3.2.1 To Combo Box dng wizard

Cng c Wizard c th to c 2 loi Combo Box sau: l Combo Box c

ngun d liu l mt bng/ truy vn hoc l mt dy gi tr t vo thuc tnh Row

Source, hoc xy dng Combo cho php tm kim.

76

Cch to nh sau:

Bc 1: Chn chc nng Control Wizard bng cch bm vo biu tng Control

Wizard trn vng Control ca th Design (nu n cha bt).

Bc 2: Chn nt Combo Box trn thanh cng c

Bc 3: Ko mt trng ca bng/ truy vn ngun vo mu biu. Access s to mt

Combo Box buc vo trng ny.

Bc 4: Ln lt tr li cc cu hi do Wizard t ra xc nh ngun d liu v cc

c trng khc ca Combo Box. Sau khi tr li mt cu hi bm Next sang cu hi

tip theo, cui cng bm Finish.

V d 1: To Combo c cc gi tr ly t mt bng/truy vn:

Gi s to nt Combo Box MaH trong v d trn bng cch dng Wizard. D liu

ngun ca Combo Box MaH l ct MaH, TenH ca bng Hang nhng ch buc vo

MaH, Gi s ang mn hnh thit k Form (ngun d liu l bng ChitietHD). Ta

thc hin nh sau:

Bc 1: Bt chc nng Control Wizard

Bc 2: Chn Combo Box trn hp cng c

Bc 3: Ko trng [MaH] t hp Field List vo Form. kt qu s hin ra trong hnh

4.13

Hnh 4.13: Hp thoi Combo Box Wizard

Bc 4. Chn la chn th nht, ri bm Next, s hin ra danh sch cc bng/ truy vn

ngun ca Combo Box. Hnh 4.14

77

Hnh 4.14

Bc 5. Chn bng Hang lm ngun d liu, tip tc bm Next. Kt qu s hin ra

danh sch cc trng ca bng/truy vn va chn.

Bc 6. Chn cc trng a vo danh sch chn ca Combo Box. y ta chn hai

trng MaH, TenH, tip tc bm Next.

Bc 7. Access hin th ra mn hnh cho php la chn cch sp xp trong cc trng

theo chiu tng dn hay gim dn. y sp xp theo chiu tng dn ca TenH, tip

tc bm Next.

Bc 8. Bc ny ta dng chut iu chnh rng cc trng. Hoc c th bm

chn Hide key column n i trng kho khng xut hin trong bng chn.

Trong v d ny ta ko cho g nguyn c hai ct. Kt qu nh hnh 4.15

Hnh 4.15

Bc 9. Theo thit k Combo Box s c hai ct. By gi cn chn ct ly gi tr

a vo trng gn vi Combo Box. Ta chn trng MaH, tip tc bm Next.

78

Bc 10. Xc nh trng gn vi Combo Box. V ta ch ng ko trng MaH ca

bng ChitietHD vo Form, nn mc nh trng ny c chn. Tip tc bm Next

Bc 11. Sa i tiu ca nhn i km vi Combo Box, ri bm Finish. Kt qu

to c Combo Box MaH.

Khi m Form chy ta c c kt qu nh hnh 4.16

Hnh 4.16: To Combo box bng Wizard

V d 2: To Combo Box c cc gi t g vo

Gi s c CSDL tn l QuanlyGiaovien, gm cc bng sau:

DSGV(MaGV, Hoten, Matinh, chucvu, gioitinh, hocvi).

DSTINH(Matinh, tentinh)

Ta mun t chc nhp s liu cho bng DSGV.

Vi trng GioiTinh: Yu cu l mt Combo Box c 2 gi tr chn l Nam, Nu.

Ta thc hin nh sau:

Bc 1,2,3 nh trong v d 1.

Bc 4: chn nt th 2 I will type in the values that I want (ti s g cc gi tr ti

mun), nhy nt Next. Kt qu nh hnh 4.17

79

Hnh 4.17

Bc 5: Xut hin hp thoi, trong ct Col1 cho php g vo cc gi tr m sau ny s

hin th trn Combo Box. Ta g (Nam, N, Khc), Bm Next. Tip theo s n cc la

chn nh Bc 10, 11 ca v d 1. Ta c kt qu nh hnh 4.18

Hnh 4.18: To Combo t nhng gi tr nhp vo

V d 3: To Combo Box tm kim bn ghi

Trong Form hnh 4.19 ta thy c mt Combo Box nm gc bn bn phi dng

tm kim mt ging vin theo MaGV v h tn GV. Khi chn mt GV no

trong Combo Box tm kim th ni dung bn ghi tng ng ca GV ny s hin th

trn Form.

Cc bc thc hin:

Bc 1,2 nh trong v d 1, ring bc 3 khng ko cc trng v to Combo Box

khng buc vo trng no.

80

Bc 4: chn nt th 3 Find a record on my form based on, nhy nt Next.

Tip tc cho php ta chn cc trng dng tm kim (nh bc 6 trong v d 1).

y ta chn 2 trng l MaGV, Hoten, nhy nt Next.

Tip tc cho php iu chnh rng, n cc trng trong Combo Box (nh bc 8

VD1). Ti y ta hin th c 2 trng. Ny nt Next. Tip n sa li nhn cho

Combo Box (nh bc 11 trong VD1). Ta c kt qu nh hnh 4.19

Hnh 4.19: To Combo box tm kim

3.2.2 To Combo Box khng dng dng wizard

- to Combo Box khng dng wizard. Trc ht ta phi tt Control Wizard.

- S dng cc thuc tnh sau xc nh ngun d liu ca Combox.

Loi (ngun d liu) Thuc tnh

Row Rource type

Thuc tnh

Row Source

Cc bn ghi ca mt bng/ truy vn Table/ query Tn bng/ truy vn

Cc bn ghi t cu lnh Select Table/ query Cu Lnh SELECT

Danh sch gi tr t t Value list Danh sch cc gi tr

cch nhau bi du phy.

Tn cc trng ca mt bng/truy vn Field List Tn bng truy vn

Cc gi tr tr v ca mt hm trong

Access Basic Tn hm trng

81

Ngoi hai thuc tnh quan trng l Row Rource type, Row Source dng xc nh

ngun d liu cho Combo Box. Chng ta cn s dng thm mt s thuc tnh sau:

- Control Source: dng xc nh trng gn vi Combo Box ca bng d liu

ngun (i vi nhng Combo Box dng tm kim th thuc tnh ny b trng).

- Column Count: S ct trong danh sch, tnh t tri sang phi. VD: Nu t gi tr

ca thuc tnh ny l 2, th bng chn s gm 2 ct cha gi tr hai trng u ca

ngun d liu.

- Bound Column: Ct c chn lm ngun d liu ca danh sch. VD: Nu t l 2

th gi tr ct 2 s c chn, cc ct khc ch ng vai tr hin th.

- Column widths:2;1.5( rng cc ct, nu vit nh trn th rng ct mt l 2cm,

ct hai l 1.5cm). Nu cho rng bng 0 th ct khng hin th.

- Limit To List: No/Yes(Yes: ch chn trong danh sch, No: c th nhp gi tr ngoi

danh sch)

- Width: 3.5cm(b rng ca danh sach=tng b rng cc ct)

- Hieght: 5cm(chiu cao ca danh sch. Danh sch c c th nhiu hng nhng ch

cho hin ra cc hng trong phm vi 5cm).

V d 3:

Gi s c CSDL tn l QuanlyGiaovien, gm cc bng sau:

DSGV(MaGV, Hoten, Matinh, chucvu, gioitinh, hocvi).

DSTINH(Matinh, tentinh)

Ta mun t chc nhp s liu cho bng DSGV khng dng Wizard.

Trong Form ny gm:

- Trng MaGV, Hoten, chucvu, hocvi g trc tip t bn phm

- Trng Matinh l mt Combo Box, vi d liu ngun t bng DSTINH

- Trng Gioitinh chn t mt Combo box vi hai gi tr Nam, Nu

Sau y ch trnh by cch xy dng hai Combo Box.

Gi s ang mn hnh thit k Form vi bng d liu ngun l DSGV.

Combo Box MaTinh:

82

Bc 1: Bm nt Combo Box trn thanh

ToolBox ko v th vo Form

Bc 2: Nhy chut phi chn Properties

m bng thuc tnh ca Combo Box.

Xc nh gi tr cc thuc tnh nh sau:

Name: t tn l CBTinh

Control Source: Matinh

Row Source type: Table/query

Row Source: DSTinh

Column Count: 2, hin th c 2 ct Matinh,

TenTinh

Bound Column: 1. Buc vo ct Matinh

Column widths: trng th Access s ly bng

rng ca trng .

Limit To List: No

Bc 4: nhy chut chn vo nhn i km t tn nhn l: MaTinh

Combo Box Gioitinh

Bc 1: Bm nt Combo Box trn thanh ToolBox

ko v th vo Form

Bc 2: Nhy chut phi chn Properties m

bng thuc tnh ca Combo Box.

Xc nh gi tr cc thuc tnh nh sau:

Name: t tn l CBGioitinh

Control Source: Gioitinh

Row Source type:Values List

Row Source: Nam;Nu

Column Count:1

Bound Column: 1

Column widths:2cm

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Limit To List: No

Bc 4: nhy chut chn vo nhn i km t tn nhn l: Gioitinh

3.3 iu khin Command Button

Nt lnh (Command Button) l cc nt nm trn Form, khi ta nhy chut ln nt lnh

ny my s thc hin mt cng vic no . Trn Form Hnh 4.19 nn c ba nt lnh

Thm mi dng b xung bn ghi mi, Xa dng xo bn ghi hin hnh,

Tm kim dng tm kim bn ghi theo trng hin ti.

Khi to cc nt lnh ta cng c th dng Wizard hoc khng dng Wizard. Sau y

trnh by cch to bng Wizard.

Qu trnh to nt lnh Thm mi:

Bc 1: Nhy chut vo nt Control Wizards.

Bc 2: Nhy chut vo nt Command Button trn thanh Toolbox v ko v t vo

Form. Xut hin hp thoi nh hnh 4.20

Hnh 4.20: To nt bng Wizard

Bc 3: Trong khung Categories chn Record Operations (cc thao tc v bn

ghi), trong khung Actions chn Add New Record, nhy nt Next.

Bc 4: Ti y ta chn mc Text, nhp vn bn s hin th trn nt lnh l Thm

mi thay cho vn bn ngm nh Add Record (ta cng c th chn mt biu tng

ho hin trn nt lnh), nhy nt Next.

Bc 5: t tn cho nt lnh l Themmoi thay cho tn ngm nh, nhy nt Finish.

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Ta thy trong hnh 4.20 cho php ta la chn rt nhiu hnh ng m nt lnh c th

thc hin:

- Nhm Record Navigation (di chuyn bn ghi c cc chc nng): Find next, Find

Record, Go to first record, Go to last record, Go to next record, Go to previous record.

- Nhm Record Operations (cc thao tc trn bn ghi): Add new record, Delete record,

Duplicate record, Print record, Save record, Undo record.

- Nhm Form Operations (cc thao tc v mu biu): Apply Form Filter, Close Form,

Edit Form Filter, Open Form, Open Page, Print a Form, Print Current Form, Refresh

Form Data.

- Nhm Report Operations (cc thao tc v bo co): Mail report, Preview report, Print

report, Sent report.

- Nhm Application (chng tnh ng dng): Quit Application, Run Application, Run

MS Excel, Run MS Word.

- Nhm Miscellaneous (hn hp): Auto Dialer, Print Table, Run Macro, Run Query.

Nh vy vic to nt Xo cng tng t, ti bc 3 ta chn nh sau: trong khung

Categories chn Record Operations, trong khung Actions chn Delete Record.

Vic to nt Tm kim ti bc 3 ta chn nh sau: khung Categories chn Record

Navigation , trong khung Actions chn Find Record.

3.4 Thit k dng Main Sub Form

Phn ny trnh by cch t chc nhp, hin th d liu ng thi trn nhiu

bng c quan h vi nhau, trong c mt bng chnh v mi bng ph l quan h

mt nhiu. Cch t chc nh sau:

+ Xy dng cho mi bng mt mu biu. Mu biu ng vi bng chnh gi l

mu biu chnh, cc mu biu cn li gi l mu biu ph.

+ Trn mu biu chnh to cc iu khin Sub Form buc vo cc mu biu

ph. S dng cc thuc tnh ca iu khin Sub Form thit lp mi quan h gia

mu biu chnh v mu biu ph, sao cho trn iu khin Sub Form ch th hin cc

bn ghi ca mu biu ph c lin quan n bn ghi ang xt trn mu biu chnh.

+ Trong mt mu biu chnh c th c nhiu mu biu ph (gi l mu biu ph

cp mt). S mu biu ph cp mt l khng hn ch.

85

+ Trong mi mu biu ph cp mt cho php t cc mu biu ph khc (gi l

mu biu ph cp hai).

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