首先感谢大家的回复。
表A如下
id class
a b
a b1
c d
e f
=====
表B如下
id class check
a b 1
a b1 0
=====
现在,就可以把A表中的
c d
e f
放入到表b中去。
感谢您的回复。
表A如下
id class
a b
a b1
c d
e f
=====
表B如下
id class check
a b 1
a b1 0
=====
现在,就可以把A表中的
c d
e f
放入到表b中去。
感谢您的回复。
SELECT * ,
0
FROM A
WHERE NOT EXISTS ( SELECT *
FROM B
WHERE A.id = B.id
AND B.class = A.class );SELECT * FROM B
我希望B表结果如下:
表B如下
id class check
a b 1
a b1 0
c d
e f
id class check
a b 1
a b1 0
c d 0
e f 0
check字段,在刚从A表拿来插入时候,初值是0,然后在其他条件下,会被更新成1
SELECT uid, class2 FROM view_aaa ; 这句话,执行正常
uid class2
4 134
4 135
5 135
6 135
===============然后,看表B,也就是 shizi_certificate_member (师资授权)的前两列的数据,来自于表A的uid, class2,最开始为空.以下语句指行正常:
SELECT view_aaa.uid, view_aaa.class2 FROM view_aaa, shizi_certificate_member
WHERE view_aaa.uid=shizi_certificate_member.uid
and view_aaa.class2 = shizi_certificate_member.columnid
==============================
uid class2
结果为空,因为 shizi_certificate_member 本身为空。最后,上面两个sql语句结合起来看:
SELECT uid, class2 FROM view_aaa
WHERE NOT EXISTS (SELECT view_aaa.uid, view_aaa.class2 FROM view_aaa, shizi_certificate_member
WHERE view_aaa.uid=shizi_certificate_member.uid
and view_aaa.class2 = shizi_certificate_member.columnid);
执行结果如下:
[SQL]#SELECT * FROM view_aaa
#SELECT uid, class2, 0 FROM view_aaa;SELECT uid, class2 FROM view_aaa
WHERE NOT EXISTS (SELECT view_aaa.uid, view_aaa.class2 FROM view_aaa, shizi_certificate_member
WHERE view_aaa.uid=shizi_certificate_member.uid
and view_aaa.class2 = shizi_certificate_member.columnid);
[Err] 1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '(SELECT view_aaa.uid, view_aaa.class2 FROM view_aaa, shizi_certificate_member
' at line 5我现在还没有明白,为何出错了。
还请大家来帮帮我吧,非常感谢大家
SELECT view_aaa.uid, class2 FROM view_aaa
WHERE NOT EXISTS(
select view_aaa.uid, view_aaa.class2 from shizi_certificate_member, view_aaa
WHERE view_aaa.uid = shizi_certificate_member.uid
and view_aaa.class2 = shizi_certificate_member.columnid )请批评指点,看看有没有错误。
感谢您的回复。
insert into shizi_certificate_member (uid, columnid)
SELECT view_aaa.uid, class2 FROM view_aaa
WHERE NOT EXISTS(
select 1 from shizi_certificate_member, view_aaa
WHERE view_aaa.uid = shizi_certificate_member.uid
and view_aaa.class2 = shizi_certificate_member.columnid )