MySQL使用判断

MySQL> SELECT CASE 1 WHEN 1 THEN one

        -> WHEN 2 THEN two ELSE more END;

        -> one

mysql> SELECT CASE WHEN 1>0 THEN true ELSE false END;

        -> true

mysql> SELECT CASE BINARY B

        -> WHEN a THEN 1 WHEN b THEN 2 END;

        -> NULL

mysql> SELECT IF(1>2,2,3);

        -> 3

mysql> SELECT IF(1<2,yes ,no);

        -> yes
-- strcmp 比较两字符串

mysql> SELECT IF(STRCMP(test,test1),no,yes);

        -> no

mysql> SELECT IF(null,1,0);

        -> 0

mysql> SELECT IF(0.1<>0,1,0);

        -> 1