參數化查詢不限制在MSSQL服務器

Question

我有一個項目正在工作，我一直在測試我的查詢，看看他們是如何工作的，但問題是當我傳遞一個參數到查詢它不是限制它的參數我通過。

下面是查詢語法：

SELECT C.*, 
      F.Bank_VNO, 
      F.sname 
    FROM customer C 
      LEFT JOIN fssign F 
        ON c.cust_no = f.cust_no 
        AND F.cust_no = '100055' 
      LEFT JOIN (SELECT Min(ac_no) ac_no 
         FROM loans 
         WHERE full_paid = '0' 
         GROUP BY ac_no) AS l 
        ON c.cust_no = l.ac_no 
        AND cust_type = 'BUS' 

Answer 1

我認爲這不是很清楚你的意思，但可能是你應該刪除GROUP BY：

SELECT C.* 
     ,F.Bank_VNO 
     ,F.sname 
    FROM customer C 
    LEFT JOIN fssign F ON c.cust_no = f.cust_no 
       AND F.cust_no = '100055' 
    LEFT JOIN (SELECT MIN(ac_no) ac_no 
       FROM loans 
       WHERE full_paid = '0' 
/*    GROUP BY ac_no */ 
     ) AS l ON c.cust_no = l.ac_no 
     AND cust_type = 'BUS' 

可能是你想要的查詢要寫的是：

SELECT C.* 
     ,F.Bank_VNO 
     ,F.sname 
FROM customer C 
INNER JOIN fssign F ON c.cust_no = f.cust_no      
INNER JOIN (SELECT MIN(ac_no) ac_no 
      FROM loans 
      WHERE full_paid = '0' 
      ) AS l ON c.cust_no = l.ac_no 
WHERE C.cust_type = 'BUS' 
AND F.cust_no = '100055' 

Answer 2

Left Join不會過濾記錄。它將帶來左表中的所有記錄，除非您將過濾器置於Where子句中。

我想你只想在cust_type = 'BUS'的記錄。將過濾器移至Where子句。假設cust_type列是從customer表

SELECT C.*, 
      F.Bank_VNO, 
      F.sname 
    FROM customer C 
      LEFT JOIN fssign F 
        ON c.cust_no = f.cust_no 
        AND F.cust_no = '100055' 
      LEFT JOIN (SELECT Min(ac_no) ac_no 
         FROM loans 
         WHERE full_paid = '0' 
         GROUP BY ac_no) AS l -- This query does not make more sense 
        ON c.cust_no = l.ac_no 
Where C.cust_type = 'BUS'