在mysql中创建存储过程时出错答案

【问题标题】：Error in creating store procedure in mysql在mysql中创建存储过程时出错
【发布时间】：2015-12-03 11:12:08
【问题描述】：

执行下面提到的脚本时出现错误

您的 SQL 语法有错误；检查手册对应于您的 MySQL 服务器版本，以便使用正确的语法靠近'$$

DROP PROCEDURE IF EXISTS `GetTopParentGivenDepth`$$

CREATE DEFINER=`root`@`localhost` PROCEDURE `GetTopParentGivenDepth`(GivenDepth INT)
BEGIN
    DECLARE X,Y,x1,x2 INT;
    SET X = 0;
    SET Y = 1;
    SET @SQ = 'SELECT DISTINCT A0.id FROM categories A0';
    WHILE Y < GivenDepth DO
        SET @SQ = CONCAT(@SQ,' INNER JOIN categories A',Y,' ON A',X,'.id = A',Y,'.parent_id');
        SET X = Y;
        SET Y = X + 1;
    END WHILE;
    SET @SQ = CONCAT(@SQ,' WHERE A0.parent_id = 0');
    SELECT @SQ;
    PREPARE stmt FROM @SQ;
    EXECUTE stmt;
    DEALLOCATE PREPARE stmt;
END$$

【问题讨论】：

标签： mysql database stored-procedures

【解决方案1】：

在创建过程之前缺少 DELIMITER

DELIMITER $$

DROP PROCEDURE IF EXISTS `GetTopParentGivenDepth`$$

CREATE DEFINER=`root`@`localhost` PROCEDURE `GetTopParentGivenDepth`(GivenDepth INT)
BEGIN
    DECLARE X,Y,x1,x2 INT;
    SET X = 0;
    SET Y = 1;
    SET @SQ = 'SELECT DISTINCT A0.id FROM categories A0';
    WHILE Y < GivenDepth DO
        SET @SQ = CONCAT(@SQ,' INNER JOIN categories A',Y,' ON A',X,'.id = A',Y,'.parent_id');
        SET X = Y;
        SET Y = X + 1;
    END WHILE;
    SET @SQ = CONCAT(@SQ,' WHERE A0.parent_id = 0');
    SELECT @SQ;
    PREPARE stmt FROM @SQ;
    EXECUTE stmt;
    DEALLOCATE PREPARE stmt;
END$$

DELIMITER ;

【讨论】：