SQL查询可选的自定义分页，C＃的ObjectDataSource

Question

的SQL自定义分页查询为ObjectDataSource控件，允许每个请求只提供相关的特定页面数据，从而提高加载速度。

问题是如何使页面可选？

string Query = @" 
    DECLARE @PagedData int 
    SET @PagedData = 1 

    SELECT  
     CASE 
      WHEN @PagedData = 1 
      THEN (SELECT * FROM (SELECT ROW_NUMBER() OVER(ORDER BY " + _sortColumns + @") AS ResultRank, * 

       FROM dbTable 

       WHERE (FeatureString LIKE '%gold%') 

       AS ProductsWithRowNumber WHERE ResultRank > 
       " + startIndex + " AND ResultRank <= (" + startIndex + " + " + pageSize + @")) 

      ELSE (SELECT * FROM dbTable WHERE (FeatureString LIKE '%gold%')) 
     END"; 

的目标是SQL函数可以只对特定页面获取数据，或者它可以关闭寻呼获取所有的相关数据。

以上是我尝试使用CASE切换查询是否基于变量PagedData的值进行分页。但是，此方法以错误结束。

如果您需要我澄清任何事情，请让我知道，谢谢。

Answer 1

您的SQL看起来不完全正确，但假设它是正确的，这里是如何使用if语句：

string Query = @" 
DECLARE @PagedData int 
SET @PagedData = 1 

IF @PagedData = 1 
(
    SELECT * FROM (SELECT ROW_NUMBER() OVER(ORDER BY " + _sortColumns + @") AS ResultRank, * 
    FROM dbTable 
    WHERE (FeatureString LIKE '%gold%') 
     AS ProductsWithRowNumber WHERE ResultRank > 
    " + startIndex + " AND ResultRank <= (" + startIndex + " + " + pageSize + @") 
) 
ELSE 
(
    SELECT * FROM dbTable WHERE (FeatureString LIKE '%gold%') 
)"; 

https://msdn.microsoft.com/en-us/library/ms182717.aspx