MySQL Tutorial/Procedure Function/Operator

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Boolean operator: NOT

   <source lang="sql">

mysql> delimiter $$ mysql> mysql> mysql> CREATE PROCEDURE myProc()

   -> BEGIN
   ->         DECLARE a INT DEFAULT 2;
   ->         DECLARE b INT DEFAULT 3;
   ->         DECLARE c FLOAT;
   ->
   ->         IF NOT (a=b) THEN
   ->                 SELECT "a is not equal to b";
   ->         END IF;
   -> END$$

Query OK, 0 rows affected (0.00 sec) mysql> mysql> delimiter ; mysql> call myProc(); +---------------------+ | a is not equal to b | +---------------------+ | a is not equal to b | +---------------------+ 1 row in set (0.02 sec) Query OK, 0 rows affected (0.02 sec) mysql> drop procedure myProc; Query OK, 0 rows affected (0.00 sec) mysql></source>


Logic operator

   <source lang="sql">

mysql> mysql> delimiter $$ mysql> mysql> CREATE PROCEDURE myProc()

   -> BEGIN
   ->         DECLARE a INT DEFAULT 2;
   ->         DECLARE b INT DEFAULT 3;
   ->         DECLARE c FLOAT;
   ->
   ->         IF (a<b) THEN
   ->                 SELECT "a is less than b";
   ->         END IF;
   -> END$$

Query OK, 0 rows affected (0.00 sec) mysql> mysql> delimiter ; mysql> call myProc(); +------------------+ | a is less than b | +------------------+ | a is less than b | +------------------+ 1 row in set (0.00 sec) Query OK, 0 rows affected (0.02 sec) mysql> drop procedure myProc; Query OK, 0 rows affected (0.00 sec) mysql> mysql> mysql></source>