4- 数据库语言SQL

4- 数据库语言SQL

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4 数数数数数 SQL
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数数数数 数数数数数数 SQL 数数数数数数数数数数数数数数数数数数数 SQL 数数数数数 数数数数数数数数数数数数数数数数数数数数数数 SQL 数数数
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4.1 数数 1. SQL 数数数 1974 数数数 Boyce 数 Chamberlin 数数 1975~1979 数 IBM San Jose Research Lab 数数数数数数数数数数数数 System R 数数数数数数数 SQL-86 数数数数 SQL 数数 SQL-89 数 SQL-92(SQL2) 数 SQL-99(SQL3) 2. 数数 数数数 DBMS 数数数数数 SQL 数数数数数数数数数数数数数 数数数数数数数数数数
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数数数数数 DDL 数 数数数数数数数数数数数数数数数数数 数数数数数数数数 View 数 数数数数数数数数 Index 数 数数数数数 DML 数 数数数数 数数数数数数数 数数数数数 DCL 数 数数数数数数数数数数数数 4.1.1 SQL 数数数
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数数数 SQL 数数 DBMS 数数数数数数数数数 数数数数数数数 SQL 数数数数数数数数数数 数 DBMS 数数数数数 数数数 SQL 数数 SQL 数数数数数数数数数数数数数数数 数数数数数数数数数 SQL 数数数数数数数数数数数数数数数数数数数数 数数数数数数数数数数数数 SQL 数数数数数数数数数数数数数数数数数数 4.1.2 SQL 数数数
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数数数数 Create 数 Drop 数 Alter 数数数数 数数数数数 Select 数数数数数 Insert 数 Update 数 Delete 数数数数 Grant 数 Revoke 4.1.3 SQL 数数数
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数数数数 数数数数数数数数数数数数 数数数数数 Select A 1 , A 2 , . .., A n From r 1 , r 2 , . .., r m Where P 4.2 数数数数 Select Where From π A 1 , A 2 , . .., A n ( σ p (r 1 ×r 1 ×...×r m ))
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4.2.1 Select 数数数数数 数 From 数数数数数数数数数数数数数数 × 数 数 Where 数数数数数数数数数数数数数数 σ 数数数数数数数数数数数数数数 数数 Select 数数数数数数数数数数数数数数数数数数 π 数数数数 数数数数数数数数数数数数数数数数数数数数数数数数数数数数数数数数数数数数 4.2.2 Select 数数 数数数数数数数数数数数 π 数数数数数数数数数数数数数数数数数数数数
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数数数数 SQL 数数数数数数 Select 数数数数数数数数数数数数数数 (ALL) 数数数 Distinct 数数数数数数 Select Distinct sdept From Student Select All sdept From Student 数数数数数数 : 数数 数数数数数数数数
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* 数数数数数 数数 * 数数数数数数 数数 * 数 数数数数数数数数数数数数数数数数数数数数数数数数数数数 数数数数数数数数 数数数数数数数 Select * From Student Select Student.* 数 cno 数 grade From Student 数 SC Where Student.sno = SC.sno
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数数 数数数数数数数数数数数数 数数数数数数数数数 Select sno as stu_no 数 cno as course_no 数 grade From SC Select sno 数 sname 数 2001 - sage as birthday From Student
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4- 数据库语言SQL

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