MySQL Stored Routines for Project 3

delimiter //

CREATE PROCEDURE how_is_it (IN x INT)
BEGIN
   IF (x > 5) THEN
      SELECT CONCAT(x, " is higher") as answer;
   ELSE
      SELECT CONCAT(x, " is lower") as answer;
   END IF;
END
//
delimiter ;

CALL how_is_it(6);
CALL how_is_it(2);

delimiter //

CREATE FUNCTION  is_bigger (x INT)
RETURNS CHAR(3)
BEGIN
   IF (x > 5) THEN
      RETURN 'YES';
   ELSE
      RETURN 'NO';
   END IF;
END
//
delimiter ;

SELECT is_bigger(6);
SELECT is_bigger(2);


use test;

create table salary (emp_no INT, work_done INT, bonus REAL) ;

delimiter //

CREATE TRIGGER salary_bi
BEFORE INSERT ON salary
FOR EACH ROW
BEGIN
   CASE 
      WHEN new.work_done > 10 
         THEN SET new.bonus = 5000;
      WHEN new.work_done > 5
         THEN SET new.bonus = 2500;
      WHEN new.work_done > 2
         THEN SET new.bonus = 1000;
   ELSE
      SET new.bonus = 0;
   END CASE;
END
//
delimiter ;


insert into salary (emp_no, work_done,bonus) values (1,15,0);
insert into salary (emp_no, work_done,bonus) values (2,5,0);
select emp_no,work_done,bonus from salary;

delimiter //

CREATE PROCEDURE simpleproc (OUT param1 INT)
BEGIN
SELECT COUNT(*) INTO param1 FROM t;
END;
//

delimiter ;

CALL simpleproc(@a);

## Stored cursors
# http://dev.mysql.com/doc/refman/5.0/en/cursors.html

delimiter //

CREATE PROCEDURE curdemo()
BEGIN
  DECLARE done INT DEFAULT 0;
  DECLARE a CHAR(16);
  DECLARE b,c INT;
  DECLARE cur1 CURSOR FOR SELECT id,data FROM test.t1;
  DECLARE cur2 CURSOR FOR SELECT i FROM test.t2;
  DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;

  OPEN cur1;
  OPEN cur2;

  REPEAT
    FETCH cur1 INTO a, b;
    FETCH cur2 INTO c;
    IF NOT done THEN
       IF b < c THEN
          INSERT INTO test.t3 VALUES (a,b);
       ELSE
          INSERT INTO test.t3 VALUES (a,c);
       END IF;
    END IF;
  UNTIL done END REPEAT;

  CLOSE cur1;
  CLOSE cur2;
END
//
delimiter ;


# Dynamic SQL
set @query = 'select * from salary where emp_no= ? ';

prepare myStat from @query;

set @emp = 1;

EXECUTE myStat USING @emp;