Sql 参数在存储过程中不起作用

当我为月份、年份和报表源设置参数时，它们似乎没有任何影响。在执行程序时，我仍在获取所有销售信息。有人能看出哪里出了问题吗

ALTER PROCEDURE [dbo].[ddsDiscount] 
   @month INT, 
   @year INT, 
   @report_source nvarchar
AS 
   SELECT 
      isa.identifiers                           AS ISBN, 
      isa.sales_date                            AS DATO,
      isa.quantity                              AS ANTALL,
      bk.title                                  AS Tittel, 
      BV.name                                   AS BUTIKK, 
      BB.name                                   AS Forlag, 
      COALESCE(id.sales_price, isa.sales_price) AS SalesPrice 
   FROM   
      book_sales AS isa 
   LEFT JOIN 
      discount AS id ON isa.identifiers = id.identifiers 
                     AND isa.sales_date BETWEEN id.from_date AND id.to_date 
                     AND Month(isa.sales_date) = @month 
                     AND Year(isa.sales_date) = @year 
   LEFT OUTER JOIN 
      books AS BK ON BK.book_id = isa.book_id 
   LEFT OUTER JOIN 
      store AS BV ON bv.store_id = isa.store_id 
   LEFT OUTER JOIN 
      publisher AS BB ON bb.publisher_id = bk.publisher_id 
   LEFT OUTER JOIN 
      book_contributor AS BC ON BC.book_id = isa.book_id 
                       AND isa.report_source = @report_source 

---

您将条件检查放在错误的位置：

   FROM   
      book_sales AS isa 
   LEFT JOIN 
      discount AS id ON isa.identifiers = id.identifiers 
                     AND isa.sales_date BETWEEN id.from_date AND id.to_date 
                     AND Month(isa.sales_date) = @month 
                     AND Year(isa.sales_date) = @year 

这里，这些条件（由

@年

和

@月

定义）仅在有折扣的情况下进行评估-如果没有折扣，这些条件将不适用

另外：这些条件实际上与

折扣表的联接没有任何关系-它们仅引用基本
图书销售表。您应该从连接条件中删除它们，并将它们放在常规的
WHERE
子句中：

 SELECT 
      isa.identifiers                           AS ISBN, 
      isa.sales_date                            AS DATO,
      isa.quantity                              AS ANTALL,
      bk.title                                  AS Tittel, 
      BV.name                                   AS BUTIKK, 
      BB.name                                   AS Forlag, 
      COALESCE(id.sales_price, isa.sales_price) AS SalesPrice 
   FROM   
      book_sales AS isa 
   LEFT JOIN 
      discount AS id ON isa.identifiers = id.identifiers 
                     AND isa.sales_date BETWEEN id.from_date AND id.to_date 
   LEFT OUTER JOIN 
      books AS BK ON BK.book_id = isa.book_id 
   LEFT OUTER JOIN 
      store AS BV ON bv.store_id = isa.store_id 
   LEFT OUTER JOIN 
      publisher AS BB ON bb.publisher_id = bk.publisher_id 
   LEFT OUTER JOIN 
      book_contributor AS BC ON BC.book_id = isa.book_id 
                       AND isa.report_source = @report_source 
   WHERE
      Month(isa.sales_date) = @month 
      AND Year(isa.sales_date) = @year 

您的参数仅影响折扣表中的选择。将参数移动到where子句。
首先：您使用的是什么数据库？SQL只是一种查询语言——不清楚您正在针对哪个数据库编写SQL。第二：
nvarchar
不带长度的参数（在SQL Server中）的长度正好为1个字符-这是您的意图吗？？我建议您始终指定一个长度！使用
nvarchar（20）
（或任何合适的工具），而不仅仅是
nvarchar
Microsoft SQL Server 2008 R2。啊，nvarchar应该是（255）。仍然不起作用。请看我的答案-您正在检查那些
@Month
和
@Year
参数是否位于错误的位置（它们与折扣表的联接无关-将它们放在正常的
WHERE
子句中！）@Lebowski：如果这个答案帮助您解决了问题，请。这将表达你对那些花自己的时间帮助你的人的感激之情。