MySQL查询问题，当列不为空时插入行

Question

This is my query :

SELECT vehicle,
CASE 
WHEN vehicle IS NOT NULL
THEN (INSERT INTO tbl_vehicle_on_user (vehicle, userid) values
(SELECT `vehicle` FROM `tbl_missions` WHERE `id` = 4 ), (SELECT `id` FROM `tbl_users`     WHERE `id` = 12))
FROM tbl_missions WHERE id = 4;

I need to insert a row to tbl_vehicle_on_user when vehicle is not null on id 4. When i execute this query i receive this error from mysql workbench,

01:24:49 SELECT vehicle, CASE WHEN vehicle IS NOT NULL THEN (INSERT INTO tbl_vehicle_on_user (vehicle, userid) values (SELECT vehicle FROM tbl_missions WHERE id = 4 ), (SELECT id FROM tbl_users WHERE id = 12)) FROM tbl_missions WHERE id = 4 Error Code: 1064. You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'INTO tbl_vehicle_on_user (vehicle, userid) values (SELECT vehicle FROM `tbl_mi' at line 4 0.000 sec

And i get a red line under 'INTO' when i hover over it, it says 'Syntax error, unexpected INTO, expecting ('.

I don't know what it means i tried to search the web but couldn't find anything if you know how to fix this i will appreciate it if you answer my question :)

THANKS!!

Answer 1

If you already know the userid should be 12, then just use 12 instead of SELECT id FROM tbl_users WHERE id = 12 . Here is a valid insert-select statement.

INSERT INTO tbl_vehicle_on_user (vehicle, userid)
SELECT `vehicle`, 12 userid 
FROM `tbl_missions` 
WHERE `id` = 4 and vehicle is not null;