mysql用另一个表中的值更新列
我有两张桌子,看起来都像
I have two tables, both looking like
id name value
===================
1 Joe 22
2 Derk 30
我需要根据每个表中的检查名称将value
的值从tableA
复制到tableB
.
I need to copy the value of value
from tableA
to tableB
based on check name in each table.
此 UPDATE
语句的任何提示?
Any tips for this UPDATE
statement?
推荐答案
如果你需要根据tableA.value动态改变tableB.value,你可以这样做例如:
In addition to this answer if you need to change tableB.value according to tableA.value dynamically you can do for example:
UPDATE tableB
INNER JOIN tableA ON tableB.name = tableA.name
SET tableB.value = IF(tableA.value > 0, tableA.value, tableB.value)
WHERE tableA.name = 'Joe'
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