存儲過程-需要使用SELECT語句的結果

Question

以下存儲過程將返回帶有正確總數的NoOfArticles列的結果。

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 ;

到現在為止還挺好。 這是我的問題。 我希望能夠在同一存儲過程的另一個查詢中使用此“結果”，但是我不知道如何實現它。 我希望它能像這樣工作：

SET @NoOfArticles = NoOfArticles;   

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

顯然，這是行不通的，但是我希望將“結果”（ NoOfArticles ）放在變量（即@NoOfArticles ）中，然后在UPDATE語句中使用該變量（ @NoOfArticles ）。

我整整一天都沒有成功。 感謝您提供指導。 謝謝。

Answer 1

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 ;

編輯：

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 ;