MYSQL：如何根据其他两个表的条​​件在表中插入行

Question

The setup is this:

table A has columns desc and date

table B has columns desc, date and task

table C has columns keyid and type.

What I want to do is to copy some of the rows from table B to table A, where A.desc should be B.desc and A.date should be B.date. To select which rows to copy, the logic is this: "All rows such that B.task = C.keyid AND C.type='1'".

If I wanted to SELECT only the rows to copy, the query would be this:

SELECT B.desc, B.date FROM B,C WHERE B.task=C.keyid AND C.type='1'

The rows resulting from that selection need to be copied to A. I know how to write the select, but how do I write the INSERT INTO query?

Answer 1

这个未经测试的查询应该工作：

insert into tableA (tableA.desc, tableA.data) SELECT B.desc, B.date FROM B,C WHERE B.task=C.keyid AND C.type='1'

Answer 2

you can run this query:

 INSERT INTO A(desc, date) 
    VALUES (
      SELECT B.desc, B.date 
       FROM B,C 
       WHERE B.task=C.keyid AND C.type='1' 
    )

I hope it will help.

Answer 3

You can try this:

INSERT INTO table_A (desc, date)
SELECT B.desc, B.date FROM table_B as B,table_C as C WHERE B.task=C.keyid AND C.type='1'