mysql根据现有数据在一对多表中插入查询

Question

How can I make a query to enter items in a one-to-many table based upon a existing data.

For instance, on Table OTM

v_id      serv_id
1            1
2            1
3            2
4            5
5            1

Whenever serv_id is '1' I want to add to that v_id the serv_id's 6, 11, 16, 21, for instance, resulting like this:

v_id       serv_id
1             1
1             6
1             11
1             16
1             21
2             1
2             6
2             11
2             16
2             21
3             2
and so on...

Any ideas on how to accomplish that, short of grunt manual work???

Answer 1

You could use some other language to do it, easily, and there may be a better way than this, but I think it should work

INSERT INTO t1 (v_id, serv_id)
SELECT v_id, 6 FROM t1 WHERE serv_id = 1
UNION SELECT v_id, 11 FROM t1 WHERE serv_id = 1
UNION SELECT v_id, 16 FROM t1 WHERE serv_id = 1
UNION SELECT v_id, 21 FROM t1 WHERE serv_id = 1

http://sqlfiddle.com/#!2/23bc5/1