麻烦给改下下面错误的sql语句

[qqwx_1986]

要求更改查询到的第一个满足tag=0条件的改为tag=1
就是这个意思,下面是错的
update table1 set tag=1 where id=(select id from table1 where tag=0 limit 0,1);

[qq9791541]

update table1 set tag=1 where id in(select id from table1 where tag=0 limit 0,1)

[ACMAIN_CHM]

update table1 a, (select id table1 where tag=0 limit 0,1) b
set a.tag=1
where a.id=b.id

[qqwx_1986]

非常感谢两位，一楼的不行
二楼的没怎么看懂，试了下也不行

[ACMAIN_CHM]

少写了个 from

update t_qqwx_1986 a, (select id from t_qqwx_1986 where tag=0 limit 0,1) b
set a.tag=1
where a.id=b.id

测试如下.

mysql> select * from t_qqwx_1986;
+----+------+
| id | tag  |
+----+------+
|  1 |    1 |
|  2 |    0 |
|  3 |    0 |
|  4 |    1 |
+----+------+
4 rows in set (0.00 sec)

mysql> update t_qqwx_1986 a, (select id from t_qqwx_1986 where tag=0 limit 0,1) b
    -> set a.tag=1
    -> where a.id=b.id;
Query OK, 1 row affected (0.03 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select * from t_qqwx_1986;
+----+------+
| id | tag  |
+----+------+
|  1 |    1 |
|  2 |    1 |
|  3 |    0 |
|  4 |    1 |
+----+------+
4 rows in set (0.00 sec)

mysql>

[qqwx_1986]

谢了

(select id from t_qqwx_1986 where tag=0 limit 0,1) b

这个地方有点不明白什么意思，能说明下最好了

[ACMAIN_CHM]

select id from t_qqwx_1986 where tag=0 limit 0,1

这一句明白吗？

(select id from t_qqwx_1986 where tag=0 limit 0,1) b 只是定义了个子查询，

[qqwx_1986]

谢了，还是慢慢消化得了，呵呵