MySQL游标的使用

DELIMITER $$

USE `tns`$$

DROP PROCEDURE IF EXISTS `MakeFriends`$$

CREATE DEFINER=`root`@`localhost` PROCEDURE `MakeFriends`()
BEGIN
DECLARE v_adminId        BIGINT(12);
DECLARE v_currentUserID    BIGINT(12);
DECLARE v_ExistRela        INT;
DECLARE Done            INT DEFAULT 0;
DECLARE rs            CURSOR FOR SELECT userId FROM hw_user;
/* 异常处理 */
DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' SET Done = 1;

SET v_adminId = 1;

/* 打开游标 */
OPEN rs;

/* 逐个取出当前记录userId字段的值*/
FETCH NEXT FROM rs INTO v_currentUserID;
/* 遍历数据表 */
REPEAT
IF NOT Done THEN
SELECT COUNT(*) FROM hw_relationship WHERE sourceId = v_currentUserID AND targetId = v_adminId INTO v_ExistRela;
/*SELECT v_currentUserID;SELECT v_ExistRela;*/
IF v_currentUserID != v_adminId AND v_ExistRela = 0 THEN
/* insert relation records*/
INSERT INTO hw_relationship(createTime, relationType, sourceId, targetId) VALUES (NOW(), 1, v_currentUserID, v_adminId);
INSERT INTO hw_relationship(createTime, relationType, sourceId, targetId) VALUES (NOW(), 1, v_adminId, v_currentUserID);
END IF;
END IF;

FETCH NEXT FROM rs INTO v_currentUserID;

UNTIL Done END REPEAT;

/* 关闭游标 */
CLOSE rs;
END$$

DELIMITER ;