存储过程 - 需要使用SELECT语句的结果

Question

以下存储过程将返回包含正确总金额的列NoOfArticles的结果。

DELIMITER //

CREATE DEFINER=`root`@`localhost` PROCEDURE `sp_membersarea`(IN reqdTable varchar(30), IN ScannerID INT, IN MemberID INT)
BEGIN
declare NoOfArticles INT(11); 

SET @sql_text = concat("SELECT COUNT(*) AS NoOfArticles FROM t_annualdetails WHERE ScannerID = ", ScannerID);
PREPARE stmt FROM @sql_text;
EXECUTE stmt;

DEALLOCATE PREPARE stmt;

END //
DELIMITER ;

那么远那么好的。这是我的问题。我希望能够使用这个＆＃39;结果＆＃39;在同一存储过程中的另一个查询中，但我不知道如何实现它。我希望它能像这样工作：

SET @NoOfArticles = NoOfArticles;   

SET @sql_text = concat("UPDATE ", reqdTable, " SET Scan = ", @NoOfArticles, " WHERE MemberID = ", MemberID);
PREPARE stmt FROM @sql_text;
EXECUTE stmt;

显然，这不起作用，但我希望结果＆＃39; （NoOfArticles）放置在变量（即@NoOfArticles）中，然后在@NoOfArticles语句中使用该变量（UPDATE）。

我整天都没有成功。我很感激一些指导。感谢。

Answer 1

它是INTO，而不是AS

DELIMITER //

CREATE DEFINER=`root`@`localhost` PROCEDURE `sp_membersarea`(IN reqdTable varchar(30), IN ScannerID INT, IN MemberID INT)
BEGIN
declare NoOfArticles INT(11); 
/*----------------------------------here-v--into-instead-of-as-----------------*/
SET @sql_text = concat("SELECT COUNT(*) INTO NoOfArticles FROM t_annualdetails WHERE ScannerID = ", ScannerID);
PREPARE stmt FROM @sql_text;
EXECUTE stmt;

DEALLOCATE PREPARE stmt;

SET @NoOfArticles = NoOfArticles;    
SET @sql_text = concat("UPDATE ", reqdTable, " SET Scan = ", @NoOfArticles, " WHERE MemberID = ", MemberID);
PREPARE stmt FROM @sql_text;
EXECUTE stmt;

/*you can also use parameters, but not for tablename*/
SET @sql_text = concat("UPDATE ", reqdTable, " SET Scan = ? WHERE MemberID = ?");
PREPARE stmt FROM @sql_text;
EXECUTE stmt USING NoOfArticles, MemberID;

END //
DELIMITER ;

修改

DELIMITER //

CREATE DEFINER=`root`@`localhost` PROCEDURE `sp_membersarea`(IN reqdTable varchar(30), IN ScannerID INT, IN MemberID INT)
BEGIN

SET @sql_text = concat("SELECT COUNT(*) INTO @NoOfArticles FROM t_annualdetails WHERE ScannerID = ", ScannerID);
PREPARE stmt FROM @sql_text;
EXECUTE stmt;

DEALLOCATE PREPARE stmt;

/*you can also use parameters, but not for tablename*/
SET @sql_text = concat("UPDATE ", reqdTable, " SET Scan = ? WHERE MemberID = ?");
PREPARE stmt FROM @sql_text;
EXECUTE stmt USING @NoOfArticles, MemberID;

END //
DELIMITER ;