5 SQLSQLStructured Query LanguageSQLSQLSQLSQLSQL

5.1 SQL SQL2070IBMSEQUEL(Structured English Query Language)2080SQLANSISQL19984ISOSQL1990SQL

5.1.1 SQL(1)(2)(3)(4)

5.1.2 SQL SQL()5.1 SQL SQL SELECT CREATEDROPALTER INSERTUPDATEDELETE GRANTREVOKE

5.2 SQL

5.2.1 SQLSQLSQLSELECTSELECT-FROM-WHERE SELECT ALL|DISTINCT TOP Select AS , Select AS FORM ! ASLocal_Alias INNER | LEFT OUTER | RIGHT OUTER | FULL OUTER JOIN ASLocal_AliasON INTO |TO FILE ADDITIVE | TO PRINTER PROMPT | TO SCREEN PREFERENCE PreferenceNameNOCONSOLEPLAINNOWAIT WHERE 1 AND 2AND | OR GROUP BY , HAVING UNION ALL SELECT ORDER BY ASC |DESC , ASC |DESCSELECT-SQLSELECTFROMWHEREORDERGROUPUNION

SELECT FROM WHERE GROUP BY HAVING ORDER BY

1.SELECTSELECTALLDISTINCTTOP()SelectASSelectSelect*

2.FROMJOININNER | LEFTOUTER | RIGHTOUTER | FULLOUTER45.2OUTEROUTER

3.WHERE FROM

4.GROUP BY

5. HAVING GROUP BYHAVINGGROUP BY HAVING WHERE

6. ORDER BY ASCDESE

7.

UNIONUNIONSELECT-SQLUNIONALLSELECTSELECT

5.2.2 5.1zgda SELECT * FROM zgda

5.2.2 5.2zggz2000 SELECT ,, FROM zggz WHERE >2000

5.2.2 5.3zgda SELECT DISTINCT FROM zgda5.4zgda SELECT ,, FROM zgda WHERE =""

5.2.2 5.5zggz10001800 SELECT ,, FROM zggz WHERE >1000 AND

5.2.3 SQLWHEREVFP(1)NOTIN(2)NOTBETWEENAND(3)NOTLIKE

5.2.3 (1)NOT(2)LIKE_0(3)ININ(12)

5.2.3 5.6zgda SELECT DISTINCT ,, FROM zgda WHERE LIKE "" NOT SELECT DISTINCT ,, FROM zgda WHERE NOT( LIKE "")

5.2.3 5.7zgda SELECT , FROM zgda WHERE LIKE "%"

5.2.3 5.8zgda SELECT , FROM zgda WHERE IN("","") VFP, SELECT , FROM zgda WHERE ="" OR =""

5.2.4 ,5.9zgdazggz2000 SELECT zgda.,zgda.,zggz. FROM zgda,zggz WHERE (>2000) AND (zgda.=zggz.) zgda.=zggz. &&

5.2.4 5.10zgdazggz, 1900SELECT zgda.,zgda.,zgda.,zggz. FROM zgda,zggzWHERE (="") AND (>1900) AND (zgda.=zggz.)

5.2.5 ,,4(4 ),,4 P.90

5.2.5 5.111250SELECT FROM WHERE IN (SELECT FROM WHERE =1250)SELECT-FROM-WHERE,, WH1WH2, IN: SELECT FROM WHERE IN("WH1", "WH2")

5.2.5 5.121210 SELECT * FROM WHERE NOT IN(SELECT FROM WHERE

5.2.5 SELECTFROMWHERE1210WH1;WH4SQL1210 SELECT * FROM WHERE NOT IN (SELECT FROM WHERE

5.2.5 5.13E4SELECT FROM WHERE = (SELECT FROM WHERE ="E4")

5.2.5 5.1412201240BETWEENAND SELECT * FROM WHERE BETWEEN 1220 AND 1240 BETWEENAND (>=1220) AND (

5.2.5 5.15,LIKE SELECT * FROM WHERE LIKE "%" LIKE%0-

5.2.5 5.16,SELECT * FROM WHERE !="" SQL!=NOTSELECT * FROM WHERE NOT(="") NOTNOT INNOT BETWEEN

SELECT SnoSnameSdept FROM Student WHERE Sdept IN (SELECT Sdept FROM Student WHERE Sname= )

SELECT Sdept FROM Student WHERE Sname= Sno Sname Sdept 95001 IS 95002 BA 95004 cs 95004 IS Sdept IS

IS SELECT SnoSnameSdept FROM Student WHERE Sdept= IS Sno Sname Sdept 95001 IS 95002 BA 95004 cs 95004 ISSno Sname Sdept

IS95001 IS95004 IS

5.2.6 SQLORDER BYORDER BY 1 ASC | DESC, 2 ASC | DESCASC()DESC

5.2.6 5.17, SELECT * FROM ORDER BY ORDER BYDESC SELECT * FROM ORDER BY DESC

5.2.6 5.18,, SELECT * FROM ORDER BY , ORDER BY

5.2.7 SQLSQLSQL(1)COUNT(2)SUM(3)AVG(4)MAX(5)MINSELECT

5.2.7 5.19, SELECT COUNT (DISTINCT ) FROM COUNTDISTINCT SELECT COUNT(*) FROM 6

5.2.7 5.20, SELECT SUM() FROM SELECT SUM(DISTINCT ) FROM DISTINCT1250

5.2.7 5.21, SELECT SUM() FROM WHERE IN (SELECT FROM WHERE ="" OR ="")

5.2.7 [5.22] ,1210 SELECT AVG() FROM WHERE NOT IN (SELECT FROM WHERE

5.2.7 5.23,WH2 SELECT MAX() FROM WHERE ="WH2"

MAXMIN() SELECT MIN() FROM WHERE ="WH2"

5.2.8 GROUP BYGROUP BY HAVINGHAVING

5.2.8 5.24, SELECT AVG() FROM GROUP BY GROUP BYWHEREWHEREFROMHAVING

5.2.8 5.25, SELECT COUNT(*),AVG() FROM GROUP BY HAVING COUNT(*)>=2HAVINGGROUP BY HAVINGWHERE WHEREHAVINGHAVINGWHEREWHEREHAVINGHAVING

5.2.9 SQLFROM4 SELECT FROM WHERE ="" AND ="" AND .=. AND .=. AND .=.

5.2.9 SELECT FROM S, P, E W WHERE =""AND ="" AND S.=P. AND P.=E. AND E.=W.FROM S P E WSPEWSQL

5.2.10 SQLFROM FROMINNER | LEFT OUTER| RIGHTOUTER| FULLOUTER JOIN !AS Local_AliasON OUTEROUTER(outer join)

5.2.10 1.INNER JOININNER JOINJOININNER JOIN

5.2.12 5.31 SELECT .,,,, FROM JOINON .=. SELECT .,,,, FROM INNER JOIN ON .=. SELECT .,,,, FROM WHERE .=.

5.2.10 2.LEFTOUTER JOINJOINJOIN

5.2.12 5.32 SELECT .,,,, FROM LEFT JOIN ON .=.ABNULL

5.2.10 3.RIGHT OUTER JOINJOINJOIN: "WH8""E8"1200

5.2.10 5.33 SELECT .,,,, FROM RIGHT JOIN ON .=.E8

5.2.10 4.FULL OUTER JOINJOIN

5.2.10 5.34 SELECT .,,,, FROM FULL JOIN ON .=.Visual FoxProSQL SELECT

5.2.10 4SELECT .FROM ,,,WHERE .=.AND .=.AND .=.Visual FoxPro

5.2.11 UNIONSELECTSelcct1 UNION ALL Selcct2 (1)UNIONALL() (2)UNION (3)SelcctORDER BY()

5.2.11 5.35, SELECT * FROM WHERE ="" UNION SELECT * FROM WHERE =""

5.2.12 ARRAY CURSOR TABLE | DBF TO FILEADDITIVETO PRINTERINPROMPTTO SCREENPLAINNOWAIT

5.2.12 1.: TOP PERCENT::(1)PERCENT132 767(2)PERCENT0.0199.99TOPORDERBY

5.2.12 5.36, SELECT * TOP 3 FROM ORDER BY DESC5.37, 30% SELECT * TOP 30 PERCENT FROM ORDER BY

5.2.12 2.: INTO ARRAY : :

5.2.14 5.38T1 SELECT * FROM INTO ARRAY T1 T1(1,1)T1(13)

5.2.12 3.: INTO CURSOR :: dbfdbf

5.2.12 5.39dbfT2 SELECT * FROM INTO CURSOR T2 INTO CURSOR

5.2.12 4.: INTO DBF|TABLE : (dbf)

5.2.12 5.40, ,Al SELECT * TOP 3 FROM INTO TABLE A1 ORDER BY DESC

5.2.12 5. TO FILE ADDITIVE (txt)ADDITIVE

5.2.12 5.41A2.txt SELECT * TOP 3 FROM TO FILF A2 ORDER BY DESCTOINTOTO

5.2.12 6. :TO SCREEN :

5.2.12 7. :TO PRINTER PROMPT :PROMPTFROM INTO TO INTO 3ARRAYCURSORTABLE | DBF TO3

SQL SELECTVisual FoxProSQL SELECTVisual FoxPro

5.3 SQL

5.3.1 SQL3 INSERT INTO (12) VALUES(1), 2)INSERT INTO FROM ARRAY INSERT INTO FROM MEMVAR3

5.3.1 (1)1VALUES(2)2(3)3 Visual FoxProSQLVisual FoxPro

5.3.1 5.42("E7","S4","OR01",092503)INSERT INTO (,,,,)VALUES("E7","S4","OR01",{^2003-09-25},1200)

{^2003-09-25}

5.3.1 INSERT INTO () VALUES("E7","OR01")

5.3.1 INSERT INTOFROM ARRAY USE &&SCATTER to A1 &&A1COPY STRUCTURE TO A2 &&A2INSERT INTO A2 FROM ARRAY A1 &&A1A2SELECT A2 &&A2BROWSE &&BROWSEUSE &&A2.dbfDELETE FILE A2.dbf &&A2.dbf

5.3.1 FoxPro(INSERTAPPEND)

5.3.2 UPDATE! SET1=1 ,2=2 WHERE1AND | OR 2

5.3.2 (1)! (2)SET=WHERE(3)WHERE;WHERE

5.3.2 5.43,WH110%5.49 UPDATE SET =*1.10 WHERE ="WH1 : 1UPDATE SET =+1

5.3.3 SQLDELETE FROM !WHERE1AND | OR2 (1)!(2)WHERE WHERE(3)PACKREACLL

5.3.3 5.44WH2DELETE FROM WHERE ="WH2"SQL DELETEPACK

5.4 SQLVisual FoxPro

5.4.1 3Visual FoxProSQLCREATE TABLESQLSQL

5.4.1 CREATE TABLE |DBF 1NAME FREE (1 (,) NULL | NOT NULL CHECK 1ERROR 1 DEFAULT 1 PRIMARY KEY | UNIQUE REFERENCES 2TAG1 NOCPTRANS,2 ,PRIMARY KEY2TAG2 |,UNIQUE3TAG3 ,FOREIGN KEY4TAG4NODUP REFERENCES3TAG 5 ,CHECK2ERROR 2 ) |FROM ARRAY

5.4.1 CREATE TABLE3(1)TABLEDBF(2)(3) NAME128(4)FREE(5) 1 (, ) (6)NULLNOT NULLNOT NULL(7)CHECK1(8)ERROR1CHECKVFP(9)DEFAULT(10)PRIMARY KEYUNIQUE(11)REFERENCES TAG (12)CHECK 2ERROR 2 (13)FROM ARRAY SQL

5.4.1 5.451CREATE DATABASE D:VFP11 &&1SQL CREATE1OPEN DATABASE 1 &&1CREATE TABLE D:VFP11 ( C (5) PRIMARY KEY, C (10), I CHECK (>0) ERROR "0!") &&1

5.4.1 :(1)PRIMARY KEY(2)CHECK(>0) 1

5.4.1 5.46SQL CREATE 1CREATE TABLE D:VFP11( C (5), C (5), C (5) PRIMARY KEY, D) SQL CREATE4

5.4.1 :(1)SQL CREATESET EXCLUSIVE(2)(FREE)NAMECHECKDEFAULTFOREIGN KEYPRIMARY KEYREFERENCES

5.4.2 DROP TABLE DROP TABLEDBFDBFDBC

5.4.3 SQLALTER TABLE

5.4.3 1.1ALTER TABLEALTER TABLE 1 ADD | ALTER COLUMN1() NULL | NOT NULLCHECK1 ERRORDEFAULT1 PRIMARY KEY | UNIQUEREFERENCES 2 TAG 1NOCPTRANS

5.4.3 (1)1(2)ADD COLUMNADDCHECKPRIMARY KEYUNIQUE(3)ALTER COLUMNALTERCHECKCHECKPRIMARY KEYUNIQUE

5.4.3 5.471 ALTER TABLE 1 ADD I CHECK >0 ERROR "0!"

5.4.3 5.48156ALTER TABLE 1 ALTER C(6);

5.4.3 2.2 DEFAULTCHECKALTER TABLEALTER COLUMN NULL | NOT NULL SET DEFAULT SET CHECK ERROR DROP DEFAULT DROP CHECK

5.4.3 (1)(2)ALTER COLUMN (3)NULL | NOT NULL(4)SET DEFAULT (5)SET CHECK ERROR (6)DROP DEFAULT(7)DROP CHECK

5.4.3 5.49ALTER TABLE 1 ALTER SET CHECK >0 ERROR "0"

5.4.3 5.50ALTER TABLE 1 ALTER DROP CHECK 3

5.4.3 3.3 ALTER TABLEDROP COLUMN1 SET CHECK1ERROR DROP CHECK ADD PRIMARY KEY1TAG1FOR2 DROP PRIMARY KEY ADD UNIQUE 2TAG 2FOR3 DROP UNIQUE TAG3 ADD FOREIGN KEY3TAG4FOR4 REFERENCES 2 TAG4 DROP FOREIGN KEY TAG5SAVE RENAME COLUMN2TO3 NOVALIDATE

5.4.3 (1)DROPCOLUMN (2)SET CHECK ERRORDROP CHECK (3)ADD PRIMARY KEY TAG DROP PRIMARY KEY(4)ADD UNIQUE TAG DROP UIQUE TAG(5)ADD FOREIGN KEY()(6)DROP FOREIGN KEY TAGSAVE(7)RENAME COLUMN 2TO323(8)NOVALIDATEDEFAULTFOREIGN KEYPRIMARY KEYREFERENCESSET

5.4.3 5.511ALTER TABLE 1 RENAME COLUMN TO

5.4.3 5.521ALTER TABLE 1 DROP COLUMN

5.4.3 5.531()e1ALTER TABLE 1 ADD UNIQUE + TAG e1

5.4.3 5.541e1 ALTER TABLE 1 DROP UNIQUE TAG e1

5.4.4 Visual FoxPro

5.4.4 CREATESQLVIEW(1 ,2 )AS(1)SELECT(2)1.

5.4.4 5.55CREATE VIEW W1 AS SELECT , FROM 1.

5.4.4 W1 SELECT * FROM W1 SELECT , FROM W1 SELECT , FROM

5.4.4 5.56,CREATE VIEW W2 AS;SELECT * FROM WHERE ="" W2

5.4.4 2.

5.4.4 5.57,, CREATE VIEW W3 AS SELECT out.,out.,out.,out.,out. FROM out WHERE = (SELECT MAX()FROM inner1 WHERE out.=inner1.) SELECT * FROM W3

5.4.4 5.58CREATE VIEW W4 AS SELECT ,, FROM , WHERE .=.

5.4.4 3. SELECT

5.4.4 5.593CREATE VIEW W5 AS SELECT , AS ,*12 AS FROM SELECTAS12;

5.4.4 4. DROP VIEWVFPDELETE VIEW

5.4.4 5.60 W4 DROP VIEW W4

5.4.4 5. Visual FoxProVisual FoxPro;

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