Mysql crashed on conditional insert - mysql

Question

I need some condition on insert statement to prevent unauthorized insertions.
I wrote something like this:
INSERT INTO `fund` (amount,description)
SELECT 1000,'Some description'
WHERE 12 IN (SELECT id FROM users WHERE allow_add=1)
Where 12 is the id of current user.
But mysql process stopped unexpectedly!
I use XAMPP with MySQL version: 5.5.5-10.1.13-MariaDB.
Note that I ran this code before this in SQL Server without any problem.
Any Idea?

Answer 1

From users and Where exists work so maybe a bug with in?
MariaDB [sandbox]> delete from t where att = 3;
Query OK, 2 rows affected (0.04 sec)
MariaDB [sandbox]>
MariaDB [sandbox]> select * from t;
+------+------+
| id | att |
+------+------+
| 1 | 1 |
| 1 | 2 |
| 2 | 0 |
+------+------+
3 rows in set (0.00 sec)
MariaDB [sandbox]>
MariaDB [sandbox]> insert into t(id,att)
-> select 4,3
-> from users
-> where id = 1;
Query OK, 1 row affected (0.05 sec)
Records: 1 Duplicates: 0 Warnings: 0
MariaDB [sandbox]>
MariaDB [sandbox]>
MariaDB [sandbox]> select * from t;
+------+------+
| id | att |
+------+------+
| 1 | 1 |
| 1 | 2 |
| 2 | 0 |
| 4 | 3 |
+------+------+
4 rows in set (0.00 sec)
MariaDB [sandbox]>
MariaDB [sandbox]> insert into t(id,att)
-> select 4,3
-> where exists (select 1 from users where id = 1);
Query OK, 1 row affected (0.02 sec)
Records: 1 Duplicates: 0 Warnings: 0
MariaDB [sandbox]>
MariaDB [sandbox]> select * from t;
+------+------+
| id | att |
+------+------+
| 1 | 1 |
| 1 | 2 |
| 2 | 0 |
| 4 | 3 |
| 4 | 3 |
+------+------+
5 rows in set (0.00 sec)

Answer 2

Add semicolon(;) to your query, and what desc is doing in query. It will describe the table structure and its attributes.

Answer 3

It is not a proper way to authorize insertions in database. Instead, you can use programming based solution for this problem.
In PHP, a proper solution could be:-
if ($user->allow_add == 1){ //where $user is the User instance for current user
$sql->query("INSERT INTO `fund` (amount,desc) VALUES(1000,'Some desc')");
}

Answer 4

Try This:
INSERT INTO `fund` (amount,desc)
SELECT 1000 as amt,'Some desc' as des FROM users WHERE allow_add=1 LIMIT 12

Answer 5

With thanks to P.Salmon answer, I found the solution. It seems that MySQL needs FROM statement in conditional SELECT, unlike the SQL Server. So, I add a temporary table name as below:
INSERT INTO `fund` (amount,description)
SELECT 1000,'Some description'
FROM (SELECT 1) t
WHERE 12 IN (SELECT id FROM users WHERE allow_add=1)