Mysql select statement contains where clause so unsuitable for insert into - mysql

Question

I'm very inexperienced. I've prepared a select statement which gives the information I need to populate a matches table. However it is not suitable because it contains a where clause. Is there a different way to use it, or how can I change it so that it is suitable for INSERT INTO.
The tables are as follows:-
match_order
match_order_id||match_descrip||first_player||second_player
1 1v2 1 2
2 1v3 1 3
3 2v3 2 3
4 1v4 1 4
5 2v4 2 4
6 3v4 3 4
entries
entry_id||round_id||league_id||box_id||box_position
1 1 1 1 1
2 1 1 1 2
3 1 1 1 3
4 1 2 1 4
5 1 2 1 2
6 1 2 1 1
7 1 2 1 1
matches
match_id||round_id||league_id||box_id||match_order_id||player1||player2
I need to insert new rows every month for a new round of matches. League size, box size & positions change each month.
This is the statement which gives the correct rows.
SELECT e.round_id, e.league_id, e.box_id, mo.match_order_id, e.entry_id as player1, e1.entry_id as player2
FROM match_order mo
LEFT JOIN entries e ON mo.first_player = e.box_position
LEFT JOIN entries e1 ON mo.second_player = e1.box_position
WHERE e.round_id = e1.round_id AND e.league_id = e1.league_id AND e.box_id = e1.box_id
ORDER BY round_id, league_id, box_id, match_order_id
Any help & advise would be greatly appreciated.
Thank you

Answer 1

Assuming match_id is an auto-increment column, you have the data for the other columns. You can just add the INSERT statement before your SELECT.
INSERT INTO matches(round_id, leage_id, box_id, match_order_id, player1, player2)
SELECT e.round_id, e.league_id, e.box_id, mo.match_order_id, e.entry_id as player1, e1.entry_id as player2
FROM match_order mo
LEFT JOIN entries e ON mo.first_player = e.box_position
LEFT JOIN entries e1 ON mo.second_player = e1.box_position
WHERE e.round_id = e1.round_id AND e.league_id = e1.league_id AND e.box_id = e1.box_id