update a set uid=b.uid from table_student a,table_teacher b where a.class=b.class
update a set uid=b.uid from cdb_teacher a, cdb_members b where a.username=b.username#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 'from cdb_teacher a, cdb_members b where a.username=b.username' at line 1
#1楼 得分:0回复于:2011-05-16 22:02:12SQL codeupdate a set uid=b.uid from table_student a,table_teacher b where a.class=b.class
结果不好啊,这是怎么回事啊
select * from table_teacher , table_student where table_student.uid=table_teacher.uid and table_teacher.class=table_student.class
#7楼 得分:0回复于:2011-05-16 22:31:58 select * from table_teacher , table_student where table_student.uid=table_teacher.uid and table_teacher.class=table_student.class 这样只是取出数据吧,那要更新数据怎么实现呢
update table_teacher , table_student set table_student.uid=table_teacher.uid where table_teacher.class=table_student.class
谢谢楼上的大虾,我刚实验出来跟你后面的语句 update table_teacher , table_student set table_student.uid=table_teacher.uid where table_teacher.class=table_student.class 一样哇咔咔非常感谢!!
from table_student a,table_teacher b where a.class=b.class
from table_student a,table_teacher b where a.class=b.class
结果不好啊,这是怎么回事啊
from table_teacher , table_student
where table_student.uid=table_teacher.uid and table_teacher.class=table_student.class
select *
from table_teacher , table_student
where table_student.uid=table_teacher.uid and table_teacher.class=table_student.class 这样只是取出数据吧,那要更新数据怎么实现呢
set table_student.uid=table_teacher.uid
where table_teacher.class=table_student.class
建议你列出你的表结构,并提供测试数据以及基于这些测试数据的所对应正确结果。
参考一下这个贴子的提问方式http://topic.csdn.net/u/20091130/20/8343ee6a-417c-4c2d-9415-fa46604a00cf.html
1. 你的 create table xxx .. 语句
2. 你的 insert into xxx ... 语句
3. 结果是什么样,(并给以简单的算法描述)
4. 你用的数据库名称和版本(经常有人在MS SQL server版问 MySQL)
这样想帮你的人可以直接搭建和你相同的环境,并在给出方案前进行测试,避免文字描述理解上的误差。
update table_teacher , table_student
set table_student.uid=table_teacher.uid
where table_teacher.class=table_student.class 一样哇咔咔非常感谢!!