如何更新一个表的字段，该表是MySQL中另一个表的内部联接？

Question

I have two tables: tablea and tableb . Both of them have three columns called columna , columnb , columnc .

Now I want to do this:

If tablea.columnb equals tableb.columnb ,then set tablea.columnc = tableb.columnc . I have written the sql and it works well, but I think that there must be a better way to do this? Can anyone help me to optimize my sql statement, or is there any other way?

UPDATE tablea ta 
SET 
ta.columnc = (
              SELECT columnc FROM tableb
              WHERE ta.columnb = tableb.columnb
             )
WHERE ta.columnb IN (
                     SELECT columnb FROM tableb
                     WHERE ta.columnb = tableb.columnb
                    )

Answer 1

您可以尝试这个简单的查询

Update tablea ta,table tb set ta.columnc=tb.columnc where ta.columnb =tb.columnb;