(MOD(4, 0)) will return a null value : MOD « Math Numeric Functions « MySQL Tutorial






mysql>
mysql> SELECT MOD(4, 0) as Result;
+--------+
| Result |
+--------+
|   NULL |
+--------+
1 row in set (0.00 sec)








21.24.MOD
21.24.1.MOD(N,M), N % M, N MOD M: modulo operation. returns the remainder of N divided by M.
21.24.2.MOD(N,0) returns NULL.
21.24.3.The modulo function returns the remainder of two numbers.
21.24.4.(MOD(4, 0)) will return a null value