[英]Match 2 sql columns if = then update a different column by 1
Im looking to see if there is a match between what someone submitted in one table to a different table in the database. 我正在寻找某人在一个表中提交的内容与数据库中另一个表之间是否存在匹配项。 I can't quite figure out how to set it up. 我不太清楚如何设置它。 What im trying for is 我正在努力的是
IF tableA column A = tableB column B then table A column C = Column C + 1.
I have tried the update method but that seems to not be working for me. 我尝试了更新方法,但似乎对我不起作用。 Any help would be great. 任何帮助都会很棒。 Thanks. 谢谢。
Generally it would be this: 通常是这样的:
UPDATE TABLE_A a JOIN TABLE_B b
ON a.join_col = b.join_col AND a.column_a = b.column_b
SET a.column_c = a.column_c + 1
The join_col
value is likely the user_id so that you only update rows in TABLE_A
where that same user has the same value in TABLE_B
. join_col
值可能是user_id,因此您只更新TABLE_A
中同一用户在TABLE_A
中具有相同值的TABLE_B
。
I guess you can do this in mysql: 我猜你可以在mysql中做到这一点:
UPDATE TableA a, TableB b
SET a.ColumnC = ColumnC + 1
WHERE a.ColumnA = b.ColumnB;
如果这是你想要的
update tableA set colA=(select (case when b.colB=colA then colC+1 else colC end) from tableB b)
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