存储过程中为空参数不参与Where查询如何处理

一、存储过程

1、当存储过程传入参数很多，为空的参数不参与where语句查询如何处理

USE [数据库名]
GO
/****** Object:  StoredProcedure [dbo].[cp_Table1]    Script Date: 2018/7/9 11:48:16 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

--取得分页记录列表
ALTER PROCEDURE [dbo].[cp_存储过程名] 
    @Page  int,--页数
    @PageSize  int,--每页条数
    @Title varchar(200),--标题（查询内容）
    @RowCount  int output,--总行数
    @Downloader bit,--是否导出
AS
    DECLARE @iBeginID  int --开始分页ID
    DECLARE @iEndID  int --结束分页ID
     
    set nocount on  --提高性能
    SET @iBeginID = (@Page-1) * @PageSize + 1
    SET @iEndID = @iBeginID + @PageSize - 1
    SET @RowCount = 0
    DECLARE @Sql_GetCount NVARCHAR(MAX);
    DECLARE @Sql_Sigel NVARCHAR(MAX);
    DECLARE @DateNow DateTime =GETDATE();

    SET  @Sql_GetCount=N'
    SELECT @RowCount = COUNT(ID)  FROM Table1 WITH(NOLOCK) 
    WHERE 1=1'
    IF(LEN(@Title)>0) SET  @Sql_GetCount+=N' AND Title LIKE ''%''+@Title+''%'' '
    
    EXECUTE sp_executesql @Sql_GetCount,N' @RowCount INT OUTPUT,@Title varchar(200)',
    @RowCount =@RowCount OUTPUT,@Title =@Title

    IF(@RowCount = 0)
        RETURN 0;
         
    SET @Sql_Sigel=N'
    WITH t AS (
        SELECT ROW_NUMBER() OVER (ORDER BY OrderNum DESC) AS R_Number,
        *
        FROM Table1  WITH(NOLOCK) WHERE 1=1 '
    IF(LEN(@Title)>0) SET  @Sql_Sigel+=N' AND Title LIKE ''%''+@Title+''%'' '
    SET @Sql_Sigel+=N')
    SELECT * FROM t’
    IF(@Downloader=0) SET @Sql_Sigel+=N' WHERE  R_Number BETWEEN @iBeginID AND @iEndID;'
    EXECUTE sp_executesql @Sql_Sigel,N' @RowCount INT OUTPUT,@Title varchar(200),@iBeginID int,@iEndID int',
    @RowCount =@RowCount OUTPUT,@Title =@Title,@iBeginID=@iBeginID,@iEndID=@iEndID

结果分析：当参数较多时使用拼接sql方式可减少代码冗余，且效率更高。SELECT ROW_NUMBER() OVER (ORDER BY OrderNum DESC) AS R_Number, 此句给数据排序并每条按顺序编号，用于分页