create procedure pro_test5()
begin
declare height int default 175; //声明变量height为int类型,默认值为175
declare description varchar(50);
if height >= 180 then //判断变量height 大等于180 then然后就
set description = '高度不低于180'; //写入变量的值为字符串
elseif height >= 170 and height < 180 then //判断其他情况, 变量的值在170和180之间然后就
set description = '鏍囧噯韬潗';
else //其他所有情况
set description = '涓€鑸韩鏉;
end if;
select description; //select打印变量
end;
=========================================================
delimiter $$
-- delimiter [dɪ'lɪmɪtə] 分隔符;声明结束符号
-- procedure [prəˈsidʒər] 程序,过程 in 输入数据库,date定义变量,类型
CREATE proceduer eisc(out date varchar(20))
BEGIN
SELECT * FROM rota;
end
创建一个存储过程,将结果传给date
调用:
call eisc(@date)
select @date
DROP PROCEDURE IF EXISTS replaceStr;
DELIMITER $$
CREATE PROCEDURE `replaceStr`(INOUT oldStr VARCHAR(1024), IN replace1 VARCHAR(16), IN replace2 VARCHAR(16))
BEGIN
SET @i=0;
-- 获取参数replace1出现的次数
SET @count = CHAR_LENGTH(oldStr)-CHAR_LENGTH(REPLACE(oldStr, replace1, ''));
-- 先申明一个变量存放替换之后的字符串
SET @newStr = '';
WHILE @i <= @count
DO
SET @i=@i+1;
IF(@i != 1) THEN
SELECT CONCAT(@newStr, replace2, SUBSTRING_INDEX(SUBSTRING_INDEX(oldStr, replace1 ,@i), replace1 ,-1)) INTO @newStr;
ELSE
SELECT CONCAT(@newStr, SUBSTRING_INDEX(SUBSTRING_INDEX(oldStr, replace1, @i), replace1, -1)) INTO @newStr;
END IF;
END WHILE;
-- 把替换之后的字符串赋给旧字符串变量
SET oldStr = @newStr;
END;
// 2、调用存储过程
SET @arrayStr = '1 2 3 4 5 6 7';
CALL replaceStr(@arrayStr, ' ', '-');
SELECT @arrayStr;
1、建立一张学生表
DROP TABLE IF EXISTS `student`;
CREATE TABLE `student` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(256) DEFAULT NULL,
`class` varchar(256) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8;
-- ----------------------------
-- Records of student
-- ----------------------------
INSERT INTO `student` VALUES ('1', '张三', '1班');
INSERT INTO `student` VALUES ('2', '李四', '2班');
INSERT INTO `student` VALUES ('3', '王五', '3班');
INSERT INTO `student` VALUES ('4', '麻子', '1班');
INSERT INTO `student` VALUES ('5', '老王', '3班');
复制代码
2、建立存储过程
复制代码
DROP PROCEDURE IF EXISTS fors;
DELIMITER $$
CREATE PROCEDURE fors(OUT namess VARCHAR(1024))
BEGIN
DECLARE a VARCHAR(500);
DECLARE Done, nameCount INT DEFAULT 0 ;
DECLARE rs CURSOR FOR SELECT NAME FROM student;
DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' SET Done = 1 ;
-- 不申明结果为NULL
SET namess = '';
-- 打开游标
OPEN rs;
FETCH NEXT FROM rs INTO a;
REPEAT
SET nameCount = nameCount + 1 ;
IF(nameCount != 1 ) THEN
SELECT CONCAT(namess,',' , a) INTO namess;
ELSE
SELECT CONCAT(namess, a) INTO namess;
END IF;
FETCH NEXT FROM rs INTO a;
UNTIL Done END REPEAT;
CLOSE rs;
END
复制代码
3、调用存储过程
CALL fors(@names);
SELECT @names;
4、执行结果
张三,李四,王五,麻子,老王
1、建立一张学生表
复制代码
DROP TABLE IF EXISTS `student`;
CREATE TABLE `student` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(256) DEFAULT NULL,
`class` varchar(256) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8;
-- ----------------------------
-- Records of student
-- ----------------------------
INSERT INTO `student` VALUES ('1', '张三', '1班');
INSERT INTO `student` VALUES ('2', '李四', '2班');
INSERT INTO `student` VALUES ('3', '王五', '3班');
INSERT INTO `student` VALUES ('4', '麻子', '1班');
INSERT INTO `student` VALUES ('5', '老王', '3班');
复制代码
2、建立存储过程
复制代码
DROP PROCEDURE IF EXISTS whileFor;
DELIMITER $$
CREATE PROCEDURE whileFor(OUT namess VARCHAR(1024))
BEGIN
DECLARE a VARCHAR(500);
DECLARE i , j , Done INT DEFAULT 0 ;
-- 申明游标
DECLARE rs CURSOR FOR SELECT NAME FROM student;
DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' SET Done = 1 ;
SET namess = '' , i = 0 , j = 1;
-- 循环四次
WHILE (j < 5) DO
-- 如果不是第一次,我们这里加一个|区分
IF(j > 1) THEN
SELECT CONCAT(namess,'|') INTO namess;
END IF;
-- 打开游标
OPEN rs;
FETCH NEXT FROM rs INTO a;
REPEAT
SET i = i + 1 ;
IF(i != 1 ) THEN
SELECT CONCAT(namess,',' , a) INTO namess;
ELSE
SELECT CONCAT(namess , a) INTO namess;
END IF;
FETCH NEXT FROM rs INTO a;
UNTIL Done END REPEAT;
CLOSE rs;
SET j = j + 1;
SET Done = 0 ;
SET i = 0 ;
END WHILE;
END
复制代码
3、调用存储过程
CALL whileFor(@names);
SELECT @names;
4、执行结果
张三,李四,王五,麻子,老王|张三,李四,王五,麻子,老王|张三,李四,王五,麻子,老王|张三,李四,王五,麻子,老王
1、建立一张学生表
复制代码
DROP TABLE IF EXISTS `student`;
CREATE TABLE `student` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(256) DEFAULT NULL,
`class` varchar(256) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8;
-- ----------------------------
-- Records of student
-- ----------------------------
INSERT INTO `student` VALUES ('1', '张三', '1班');
INSERT INTO `student` VALUES ('2', '李四', '2班');
INSERT INTO `student` VALUES ('3', '王五', '3班');
INSERT INTO `student` VALUES ('4', '麻子', '1班');
INSERT INTO `student` VALUES ('5', '老王', '3班');
复制代码
2、建立存储过程
复制代码
DROP PROCEDURE IF EXISTS forFor;
DELIMITER $$
CREATE PROCEDURE forFor(OUT classNames VARCHAR(1024))
BEGIN
-- 班级名、姓名
DECLARE classs , namess VARCHAR(500);
-- 班级数量、该班级下面学生的数量、班级变量++、学生变量++
DECLARE classNumber , nameNumber, classCount , nameCount INT DEFAULT 0;
-- 建立两个游标,第一个游标用来存储班级、第二个用来存储学生姓名
DECLARE class_csr CURSOR FOR SELECT class FROM student GROUP BY class;
DECLARE name_csr CURSOR FOR SELECT NAME FROM student WHERE class = classs ;
-- 获取按班级分组之后的数量
SELECT COUNT(*) INTO classNumber FROM (SELECT COUNT(*) FROM student GROUP BY class) t;
SET classNames = '' ;
-- 打开班级游标
OPEN class_csr;
-- 开始班级游标循环
class_loop: LOOP
FETCH class_csr INTO classs ;
SET classCount = classCount +1 ;
IF(classCount != 1 ) THEN
SELECT CONCAT(classNames,',' , classs, '(') INTO classNames;
ELSE
SELECT CONCAT(classNames, classs, '(') INTO classNames;
END IF;
-- 获取该班级下面学生的数量
SELECT COUNT(*) INTO nameNumber FROM student WHERE class = classs;
-- 打开学生游标
OPEN name_csr;
-- 开始学生游标循环
name_loop: LOOP
FETCH name_csr INTO namess;
SET nameCount = nameCount +1 ;
IF(nameCount != 1 ) THEN
SELECT CONCAT(classNames,',' , namess) INTO classNames;
ELSE
SELECT CONCAT(classNames , namess) INTO classNames;
END IF;
-- 如果学生变量等于学生数量,那么就终止该游标(第一个)
IF(nameCount = nameNumber) THEN
LEAVE name_loop;
END IF;
-- 结束学生游标循环
END LOOP name_loop;
-- 关闭学生游标
CLOSE name_csr;
SET nameCount = 0 ;
SELECT CONCAT(classNames , ')') INTO classNames;
-- 如果班级变量等于班级数量,那么就终止该游标(第二个)
IF(classCount = classNumber) THEN
LEAVE class_loop;
END IF;
-- 结束班级游标循环
END LOOP class_loop;
-- 关闭班级游标
CLOSE class_csr;
END ;
复制代码
3、调用存储过程
CALL forFor(@classNames);
SELECT @classNames;
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