MySQL你如何做一個變量的準備語句？

Question

這是存儲過程，我試圖用

DELIMITER ## 
CREATE PROCEDURE exportFile() 
BEGIN 

DECLARE filename VARCHAR(255); 

SET filename = CONCAT('~/Sample',NOW(),'.csv')); 
SET @outfilestmt = concat('SELECT * INTO OUTFILE ',"'", filename,"'",' FROM Results') ; 

PREPARE stmt FROM @outfilestmt; 
EXECUTE stmt; 
DEALLOCATE PREPARE stmt; 

END ## 
DELIMITER ; 

這是錯誤我得到

ERROR 1064 (42000): 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 '); 
SET @outfilestmt = concat('SELECT * INTO OUTFILE ',"'", filename,"'",' FROM R' at line 6 

所需的結果：

call exportFile 
--~/Sample2012-03-14-10:42:51.cvs 

call exportFile 
--~/Sample2012-03-14-10:42:52.cvs 

call exportFile 
--~/Sample2012-03-14-10:42:53.cvs 

Answer 1

一分號後失蹤

SET filename = CONCAT('~/Sample',NOW(),'.csv')) 

和一個支架太多（也由Devart注意到。謝謝）。更改爲

SET filename = CONCAT('~/Sample',NOW(),'.csv'); 

經過測試確定。作品！