在mysql中使用select into local变量和prepared语句

Question

每次调用此存储过程我都会收到此错误:

#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'NULL' at line 1

什么似乎是问题？

这是代码:

DELIMITER $$

DROP PROCEDURE IF EXISTS `singledb`.`TOUR_TRANSFER`$$

CREATE DEFINER=`root`@`localhost` PROCEDURE `TOUR_TRANSFER`()
BEGIN

BEGIN -- for rubric table
            DECLARE tblRubric_rubric_id INT;
            SET @qry = concat('SELECT count(*) into ',tblRubric_rubric_id,' FROM zerodb2.tour_template');
            PREPARE statement FROM @qry;
            EXECUTE statement;

            SELECT tblRubric_rubric_id;
END;
END$$

DELIMITER ;

Answer 1

来自http://bugs.mysql.com/bug.php?id=15263:

"参数标记只能在数据值出现的地方使用,而不能用于SQL关键字,标识符等."

所以,我们做不到:

从'SELECT id INTO中预备stmt FROM？从t1';

我们不能用？而不是标识符(变量名称).

当您使用参数名称时:

PREPARE stmt FROM'SELECT id INTO rid from t1';

在正在准备的字符串中,然后服务器根本不知道您正在尝试准备的语句中的rid所引用的内容.您可以尝试在SP之外准备它,结果相同:

mysql>准备stmt从'select id into p from t1'; 错误1327(42000):未声明的变量:p

所以我只使用了用户变量,见下文:

DROP PROCEDURE IF EXISTS `singledb`.`TOUR_TRANSFER`$$
CREATE DEFINER=`root`@`localhost` PROCEDURE `TOUR_TRANSFER`()
BEGIN
BEGIN -- for rubric table
            -- DECLARE @tblRubric_rubric_id INT;

            SET @tblRubric_rubric_id := 0;
            SET @qry = 'SELECT count(*) into @tblRubric_rubric_id FROM zerodb2.tour_template';
            PREPARE statement FROM @qry;
            EXECUTE statement;
END;
END$$