MYSQL存储过程与游标学习

自己随便写了一个统计用户权限数量插入对应表的案例

CREATE TABLE IF NOT EXISTS u_user_role_count (
	`id` BIGINT NOT NULL AUTO_INCREMENT COMMENT "表ID",
	`uid` BIGINT NOT NULL COMMENT "用户ID",
	`uname` VARCHAR(16) DEFAULT NULL COMMENT "用户名",
	`rname` VARCHAR(16) DEFAULT NULL COMMENT "权限名",
	`count` BIGINT NOT NULL COMMENT "总计",
	PRIMARY KEY (id)
)ENGINE=INNODB,DEFAULT CHARSET=utf8;



###########################统计用户权限数量##############################
#存储过程

DROP PROCEDURE GetAllProducts;

DELIMITER //
CREATE PROCEDURE GetAllProducts()
BEGIN
	DECLARE UID BIGINT;
	DECLARE UNAME VARCHAR(16);
	DECLARE COUNTN INT;
	DECLARE done INT DEFAULT 0;
	DECLARE total INT;
	
	DECLARE set_user CURSOR FOR SELECT `id` FROM u_user; ##建立游标

	SELECT COUNT(id) INTO total FROM u_role;

	OPEN set_user;
	al: LOOP
		FETCH set_user INTO UID;				##遍历并使用游标,取出里面每个ID

		SELECT COUNT(u_user.id) INTO COUNTN
		FROM u_user,u_user_role,u_role
		WHERE u_user.id=UID AND u_user_role.uid=UID AND u_user_role.rid=u_role.id;	##计数权限数量
		
		SELECT `nickname` INTO UNAME FROM u_user WHERE id=UID;			##查出用户名
		
		INSERT INTO u_user_role_count (uid,uname,count) VALUES (UID,UNAME,COUNTN);	##插入对应表格
		
		set done = done+1;
		
		IF done = total THEN
			LEAVE al; 
		END IF; 
	END LOOP al;
	CLOSE set_user;

END //
DELIMITER ;

################################权限计数####################################

DROP PROCEDURE EachUser;
DELIMITER //
CREATE PROCEDURE EachUser(
	UID BIGINT
)
BEGIN
		SELECT COUNT(*)
		FROM u_user,u_user_role,u_role
		WHERE u_user.id=UID AND u_user_role.uid=UID AND u_user_role.rid=u_role.id;
END//
DELIMITER ;


################################测试#####################################

call GetAllProducts();

call EachUser(1);

CREATE TEMPORARY TABLE tmp SELECT * FROM CALL EachUser(1);

下面是统计某角色所有用户的数量

CREATE TABLE IF NOT EXISTS u_role_user_count(
	`id` BIGINT NOT NULL AUTO_INCREMENT COMMENT '主键ID',
	`rid` BIGINT NOT NULL COMMENT '角色ID',
	`rname` VARCHAR(16) NOT NULL COMMENT '角色名称',
	`count` INT NOT NULL COMMENT '计数',
	PRIMARY KEY (id)
)ENGINE=INNODB,DEFAULT CHARSET=utf8;


DROP PROCEDURE CountRoleUsers;

DELIMITER //
CREATE PROCEDURE CountRoleUsers()
BEGIN
	DECLARE RID BIGINT;
	DECLARE RNAME VARCHAR(16);
	DECLARE COUNTN INT;
	DECLARE done INT DEFAULT 0;
	DECLARE total INT;
	
	DECLARE set_role CURSOR FOR SELECT `id`,`name` FROM u_role;
	SELECT COUNT(id) INTO total FROM u_role;
	
	OPEN set_role;
	lb: LOOP

		FETCH set_role INTO RID,RNAME;
	
		SELECT COUNT(u_role.id) INTO COUNTN
		FROM u_role,u_user_role,u_user
		WHERE u_user.id=u_user_role.uid AND u_user_role.rid=RID AND u_role.id=RID;

		INSERT INTO u_role_user_count (rid,rname,count) VALUES (RID,RNAME,COUNTN);
	
		SET done=done+1;
		IF done = total THEN
			LEAVE lb; 
		END IF; 
	END LOOP lb;
	CLOSE set_role;
END //
DELIMITER ;

CALL CountRoleUsers();