SQL-语句（2）

查询

//不做总结，都是实例代码

SELECT S.S#,SNAME
FROM S,SC
WHERE S.S#=SC.S# AND C#='C2';

SELECT S.S#,SNAME
FROM S
WHERE S# IN(SELECT S#
			FROM SC
			WHERE C='C#');
SELECT S.S#,SNAME
FROM S
WHERE 'C2' IN(SELECT C#
            FROM SC
            WHERE S#=S.S#)

SELECT S#,SCORE
FROM SC
WHERE C#=‘C2’

SELECT S#,SNAME
FROM S,SC
WHERE S.S#=SC.S# AND C#=‘C2’

SELECT S#,SNAME
FROM T,C,SC,S
WHERE T.T#=C.T# AND C.C#=SC.C# AND SC.S#=S.S# AND TNAME=‘LIU’

SELECT S#
FROM SC
WHERE C#=‘C2’ OR C#=‘C4’

SELECT S#,SNAME
FROM S
WHERE S# IN(SELECT S#
FROM SC
WHERE C# IN(SELECT C#
FROM C
WHERE T# IN(SELECT T#
FROM T
WHERE T#=‘LIU’)));

SELECT X.S#
FROM SC AS X,SC AS Y
WHERE X.S#=Y.S# AND X.C#=‘C2’ AND Y.C#=‘C4’

SELECT SNAME,AGE
FROM S
WHERE S# NOT IN (SELECT S#
FROM SC
WHERE C#=‘C2’)
SELECT SNAME,SGE
FROM S
WHERE NOT EXIST(SELECT *
FROM SC
WHERE SC.S#=S.S# AND C#=‘C2’)