Question

SET @v1 := SELECT COUNT(*) FROM user_rating;
SELECT @v1

When I execute this query with set variable this error is shown.

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 'SELECT count(*) FROM user_rating' at line 1

Execution Time : 00:00:00:000
Transfer Time  : 00:00:00:000
Total Time     : 00:00:00:000

(1 row(s) returned)
Execution Time : 00:00:00:343
Transfer Time  : 00:00:00:000
Total Time     : 00:00:00:343

Answer 1

Surround that select with parentheses.

SET @v1 := (SELECT COUNT(*) FROM user_rating);
SELECT @v1;