測試用表
SET FOREIGN_KEY_CHECKS=0;
-- ----------------------------
-- Table structure for stu
-- ----------------------------
DROP TABLE IF EXISTS `stu`;
CREATE TABLE `stu` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`name` varchar(255) DEFAULT NULL,
`kecheng` varchar(255) DEFAULT NULL,
`fenshu` int(255) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=9 DEFAULT CHARSET=utf8;
-- ----------------------------
-- Records of stu
-- ----------------------------
INSERT INTO `stu` VALUES ('1', '張三', '語文', '40');
INSERT INTO `stu` VALUES ('2', '張三', '數學', '60');
INSERT INTO `stu` VALUES ('3', '李四', '數學', '110');
INSERT INTO `stu` VALUES ('4', '李四', '語文', '40');
INSERT INTO `stu` VALUES ('7', '你本來就很二', '德語', '110');
INSERT INTO `stu` VALUES ('8', '王五', '數學', null);
-- 多個out參數的存儲過程
DROP PROCEDURE IF EXISTS moreOutPro;
CREATE PROCEDURE moreOutPro(OUT outParam1 INT, OUT outParam2 INT)
BEGIN
SELECT id, fenshu INTO outParam1, outParam2 FROM stu LIMIT 1;
END;
-- CALL moreOutPro(@outParam1, @outParam2);
-- SELECT @outParam1, @outParam2;
-- 顯示存儲過程源代碼
-- SHOW CREATE PROCEDURE inPro;
-- while循環
DROP PROCEDURE IF EXISTS while_loop;
CREATE PROCEDURE while_loop(OUT outParam VARCHAR(30))
BEGIN
DECLARE str VARCHAR(30);
DECLARE i INT;
SET str = '';
SET i = 0;
WHILE i < 10
DO
SET i = i + 1;
SET str = CONCAT(str,i,' ');
END WHILE;
SELECT str;
END;
-- CALL while_loop(@outParam);
-- SELECT @outParam;
-- REPEAT循環
DROP PROCEDURE IF EXISTS repeat_loop;
CREATE PROCEDURE repeat_loop(OUT outParam VARCHAR(30))
BEGIN
DECLARE str VARCHAR(30);
DECLARE i INT;
SET str = '';
SET i = 0;
REPEAT
SET str = CONCAT(str,i,' ');
SET i = i + 1;
UNTIL i > 10
END REPEAT;
SELECT str;
END;
CALL repeat_loop(@outParam);
SELECT @outParam;
-- loop循環
DROP PROCEDURE IF EXISTS loop_test;
CREATE PROCEDURE loop_test(OUT outParam VARCHAR(30))
BEGIN
DECLARE i INT;
DECLARE str VARCHAR(30);
SET i = 0;
SET str = '';
loop_label: LOOP
IF i > 10 THEN
LEAVE loop_label; -- LEAVE語句允許您立即退出循環,而不用等待檢查條件。相當於java/c/c++中的break
END IF;
SET i = i + 1;
IF (i MOD 2) THEN -- MOD是模運算,即求餘運算,例如 1 MOD 2 = 1, 4 MOD 2 = 0, mysql中1代表true, 0代表false
ITERATE -- ITERATION語句允許您跳過剩下的那些代碼,並重新開始新的迭代.相當於java/c/c++中的continue
loop_label;
ELSE
SET str = CONCAT(str,i,' ');
END IF;
END LOOP;
SELECT str;
END;
--
-- CALL loop_test(@outParam);
-- SELECT @outParam;
-- 遊標
DROP PROCEDURE IF EXISTS corPro;
CREATE PROCEDURE corPro()
BEGIN
DECLARE finished INT DEFAULT 0;
DECLARE param int;
DECLARE cor CURSOR FOR SELECT id FROM stu;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET finished = 1;
OPEN cor;
loop_label: LOOP
FETCH cor INTO param;
IF finished = 1 THEN
LEAVE loop_label;
END IF;
UPDATE stu SET fenshu = fenshu * 2 WHERE id = param;
END LOOP loop_label;
CLOSE cor;
END;
-- CALL corPro();
-- IFNULL(expr1,expr2)
SELECT id, `name`, IFNULL(fenshu,100) FROM stu;
-- IF(expr1,expr2,expr3)
SELECT id, `name`, IF(fenshu > 80,'優秀','不行啊') FROM stu;
-- IF ELSE
DROP PROCEDURE IF EXISTS ifElsePro;
CREATE PROCEDURE ifElsePro(OUT outParam1 INT, OUT outParam VARCHAR(20))
BEGIN
SELECT MAX(fenshu) INTO outParam1 FROM stu;
IF (outParam1 > 90) THEN SET outParam = '優秀';
ELSEIF (outParam1 > 60) THEN SET outParam = '及格';
ELSE SET outParam = '不及格';
END IF;
END;
--
-- CALL ifElsePro(@score, @lev);
-- SELECT @score, @lev;
SELECT `name`, kecheng,
CASE
WHEN fenshu > 90 THEN '優秀'
WHEN fenshu > 60 THEN '及格'
ELSE '不及格'
END fenshu
FROM stu;