轉換的Microsoft SQL到mysql

Question

我這個轉換到MySQL從MSSQL，但它給我這個錯誤：

錯誤代碼：1415不允許從函數返回的結果集

什麼我做錯了嗎？

DELIMITER $$ 

CREATE FUNCTION GetPositionList (orderDetID NUMERIC) 
RETURNS NVARCHAR(200)  
DETERMINISTIC 
BEGIN 
DECLARE strToReturn NVARCHAR(50); 
DECLARE strPos NVARCHAR(50); 
DECLARE strPosOtherRes NVARCHAR(50); 
DECLARE strTPos NVARCHAR(50); 
DECLARE strTPosOtherResr NVARCHAR(50) 


SET strToReturn = ''; 
SET strPos = SELECT `POSITION` FROM orderdetails WHERE OrderID = orderDetID; 
SET strPosOtherRes = SELECT SecPosition FROM orderdetails WHERE OrderID = orderDetID; 
SET strTPos = SELECT TeamPosition FROM orderdetails WHERE OrderID = orderDetID; 
SET strTPosOtherResr = SELECT TeamSecPosition FROM orderdetails WHERE OrderID = orderDetID; 


IF(strPos != '') THEN SET strToReturn = CONCAT(strPos , ','); 
END IF; 
IF(strPosOtherRes != '') THEN SET strToReturn = CONCAT(strToReturn , strPosOtherRes , ','); 
END IF; 
IF(strTPos != '') THEN SET strToReturn = CONCAT(strToReturn , strTPos , ','); 
END IF; 
IF(strTPosOtherResr != '') THEN SET strToReturn = CONCAT(strToReturn , strTPosOtherResr , ','); 
END IF;  
RETURN SUBSTRING(strToReturn, 0, LENGTH(strToReturn)); 
END $$ 
DELIMITER ; 

Answer 1

在MySQL中爲變量選擇值的語法是select ... into。例如，你可以寫：

SELECT POSITION, SecPosition FROM orderdetails 
WHERE OrderID = orderDetID INTO strPos, strPosOtherRes; 

消息「不允許從函數返回的結果集」指的SELECT語句因爲他們的立場，現在會從功能返回一個結果，而功能只能返回單個值。