SqlDataSource SelectCommand 包含空值

Question

在服务器上运行的我的 SQL 代码。

SELECT 
    [LINE_NO], [CUST_ORDER_ID], [PART_ID], 
    [CUSTOMER_PART_ID], [MISC_REFERENCE], [PROMISE_DATE], 
    [PROMISE_DEL_DATE] 
FROM 
    [CUST_ORDER_LINE] 
WHERE 
    ([CUST_ORDER_ID] = '33742-1' 
     AND [PROMISE_DATE] IS NULL
     AND [PROMISE_DEL_DATE] IS NULL)

我的 asp.net 代码。

SelectCommand = "SELECT [LINE_NO], [CUST_ORDER_ID], [PART_ID], [CUSTOMER_PART_ID], [MISC_REFERENCE], [PROMISE_DATE], [PROMISE_DEL_DATE] FROM [CUST_ORDER_LINE] WHERE ([CUST_ORDER_ID] = ? AND [PROMISE_DATE] = ? AND [PROMISE_DEL_DATE] = ?)"

我正在使用 3 个查询字符串参数。承诺日期和承诺交付日期可以为空。但是当这些值为 null 时，它不会返回任何记录。

我该如何编程以将 SQL 更改为 'is null' 而不是 = ''。

Answer 1

我想这就是你想要的：

• 参数 1 = 订单 ID
• Param 2/3 都是 Promise Date
• 参数 4/5 都是 Promise Delivery Date

代码：

SelectCommand = "SELECT [LINE_NO], [CUST_ORDER_ID], [PART_ID], [CUSTOMER_PART_ID], [MISC_REFERENCE], [PROMISE_DATE], [PROMISE_DEL_DATE] FROM [CUST_ORDER_LINE] WHERE [CUST_ORDER_ID] = ? AND (? IS NULL OR [PROMISE_DATE] = ?) AND (? IS NULL OR [PROMISE_DEL_DATE] = ?)"

SQL 将是：

DECLARE @P1 INT, @P2 DATETIME, @P3 DATETIME

SELECT [LINE_NO], [CUST_ORDER_ID], [PART_ID], [CUSTOMER_PART_ID], [MISC_REFERENCE], [PROMISE_DATE], [PROMISE_DEL_DATE] 
FROM [CUST_ORDER_LINE] 
WHERE [CUST_ORDER_ID] = @P1 
AND (@P2 IS NULL OR [PROMISE_DATE] = @P2)
AND (@P3 IS NULL OR [PROMISE_DEL_DATE] = @P3)