SELECT T2.CHAR,T2.NUMBER,T1.NAME FROM T2,T1 WHERE T2.CHAR=T1.CHAR AND T2.NUMBER=T1.NUMBERA
试试:select name from T1 where number in (select number from T2); ------------------------------------------------------------------------------ Blog: http://blog.csdn.net/tianlesoftware 网上资源: http://tianlesoftware.download.csdn.net 相关视频:http://blog.csdn.net/tianlesoftware/archive/2009/11/27/4886500.aspx Q Q 群:62697716
SELECT * FROM T1 A WHERE EXISTS ( SELECT 1 FROM T2 WHERE CHAR=A.CHAR AND NUMBER =A.NUMBER);或者 SELECT * FROM T1 WHERE (CHAR,NUMBER) IN (SELECT CHAR,NUMBER FROM T2);
select t2.char,t2.number,name=(select name from t1 where t1.char=t2.char and t2.number = t2.number ) from t2不知道你表那个是主键.......所以条件两个都写上了
SELECT T2.CHAR,T2.NUMBER,T1.NAME FROM T2,T1 WHERE T2.CHAR=T1.CHAR AND T2.NUMBER=T1.NUMBERA
select name from T1 where number in (select number from T2);
select t2.char,t2.number,t1.name from t1,t2 where t1.char=t2.char and t1.number=t2.number
那个 后面的where中 可不可以去掉一个条件!因为 char和number本来就是一一对应的!
主键对应好就行了 select name from T1 where number in (select number from T2);
select t1.name from T1 t1,T2 t2 where t1.number = t2.number
select * from t1 t1 where t1.number in(select t2.number from t2 t2)
效率可能更高: select t1.name from t1 t1,t2 t2 where t1.number =t2.number and t1.char=t2.char
in 关键字最好少用..数据量大的时候,跑一个语句很费时间..select t1.name from T1 t1, T2 t2 where t1.number = t2.number and t2.number = ?'?'为你传入的参数值..也可以不写.如不写,就查询出全部的
FROM T2,T1
WHERE T2.CHAR=T1.CHAR AND T2.NUMBER=T1.NUMBERA
试试:select name from T1 where number in (select number from T2);
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网上资源: http://tianlesoftware.download.csdn.net
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SELECT 1 FROM T2 WHERE CHAR=A.CHAR AND NUMBER =A.NUMBER);或者
SELECT * FROM T1 WHERE (CHAR,NUMBER) IN (SELECT CHAR,NUMBER FROM T2);
select t2.char,t2.number,name=(select name from t1 where t1.char=t2.char and t2.number = t2.number ) from t2不知道你表那个是主键.......所以条件两个都写上了
FROM T2,T1
WHERE T2.CHAR=T1.CHAR AND T2.NUMBER=T1.NUMBERA
from t1,t2
where t1.char=t2.char and t1.number=t2.number
主键对应好就行了 select name from T1 where number in (select number from T2);
where t1.number in(select t2.number from t2 t2)
select t1.name from t1 t1,t2 t2 where t1.number =t2.number and t1.char=t2.char