Question

我在mysql db中有两个表：

1）dotable_new;

2）dotable_new_new

现在我需要更新我的表dotable_new_new中值为TOTAL的表dotable_new中的值TOTAL。

我正在尝试此更新查询但没有成功......你能帮助我吗？

UPDATE dotable_new a, dotable_new_new tmp
SET a.total = tmp.total
WHERE
    a.rdt IN ('tot mac')

dotable_new;

+---------+---------------+--------+-------+----+
| RDT     | TYPE          | NUMBER | TOTAL | ID |
+---------+---------------+--------+-------+----+
| tot mac | tot           |   3209 |  3249 |  1 |
+---------+---------------+--------+-------+----+

dotable_new_new

+---------+-------+----+
| RDT     | TOTAL | ID |
+---------+-------+----+
| tot mac | 10899 |  5 |
+---------+-------+----+

Answer 1

选中此项会在how to join two tables in update

上为您提供帮助

试试：

  UPDATE dotable_new a
  INNER JOIN dotable_new_new tmp ON tmp.rdt = a.rdt
  SET a.total =  tmp.total
  WHERE a.rdt = 'tot mac'

Answer 2

试试这个：

UPDATE dotable_new a
SET a.total = (SELECT tmp.total
               FROM  dotable_new_new tmp
               WHERE tmp.rdt = a.rdt)

如果您只想更新记录rdt = 'tot mac'，请将以下行添加到结尾：

WHERE a.rdt = 'tot mac'

更新在MySql中连接两个表

2 个答案: