String comparisons are performed from left to right, one character at a time:
mysql> mysql> SELECT 'abc' < 'b'; +-------------+ | 'abc' < 'b' | +-------------+ | 1 | +-------------+ 1 row in set (0.00 sec) mysql> mysql> SELECT 'bbc' <= 'b'; +--------------+ | 'bbc' <= 'b' | +--------------+ | 0 | +--------------+ 1 row in set (0.00 sec)