db2自带的whiles.db2例子

db2自带的whiles.db2例子

CREATE PROCEDURE dept_median

(IN deptNumber SMALLINT, OUT medianSalary DOUBLE)

LANGUAGE SQL

BEGIN

   DECLARE SQLCODE INTEGER;

   DECLARE SQLSTATE CHAR(5);

   DECLARE v_numRecords INT DEFAULT 1;

   DECLARE v_counter INT DEFAULT 0;

   DECLARE v_mod INT DEFAULT 0;

   DECLARE v_salary1 DOUBLE DEFAULT 0;

   DECLARE v_salary2 DOUBLE DEFAULT 0;

   DECLARE c1 CURSOR FOR

     SELECT CAST(salary AS DOUBLE) FROM staff

     WHERE DEPT = deptNumber

     ORDER BY salary;

   DECLARE EXIT HANDLER FOR NOT FOUND

     SET medianSalary = 6666;

   -- initialize OUT parameter

   SET medianSalary = 0;

   SELECT COUNT(*) INTO v_numRecords FROM staff

     WHERE DEPT = deptNumber;

   OPEN c1;

   SET v_mod = MOD(v_numRecords, 2);

   CASE v_mod

    WHEN 0 THEN

      WHILE v_counter < (v_numRecords / 2 + 1) DO

        SET v_salary1 = v_salary2;

        FETCH c1 INTO v_salary2;

        SET v_counter = v_counter + 1;

      END WHILE;

      SET medianSalary = (v_salary1 + v_salary2)/2;

    WHEN 1 THEN

      WHILE v_counter < (v_numRecords / 2 + 1) DO

        FETCH c1 INTO medianSalary;

        SET v_counter = v_counter + 1;

      END WHILE;

   END CASE;

END @