SQLSERVER 根据传入的参数拼接sql语句字符串，反馈结果集

ALTER PROCEDURE [dbo].[usp_visit_detail]
(@siteid BIGINT,
@Startime VARCHAR(15),
@Endtime VARCHAR(15),
@Aflag INT = 10, --初始值为10，非10，则表示有传入参数
@Area VARCHAR(20) = 'N', -- --初始值为N，非N，则表示有传入参数
@Nflag INT = 10, -初始值为10，非10，则表示有传入参数
@VALUE1 varchar(20) = 'N' --初始值为N，非N，则表示有传入参数

)
AS
BEGIN
DECLARE @AFlag0 varchar(50),
@NFlag0 varchar(50),
--@Sqlstr0 varchar(600),
@Sqlstr varchar(2000)

IF @AFlag = 10
SET @AFlag0 = ''
ELSE
SET @AFlag0 = ' AND AFlag=' + CAST(@AFlag AS VARCHAR)

IF @Area = 'N'
SET @Area = ''
ELSE
SET @Area = ' AND province=' + '''' + @Area + ''''

IF @NFlag = 10
SET @NFlag0 = ''
ELSE
SET @NFlag0 = ' AND NFlag=' + CAST(@NFlag AS VARCHAR)

IF @Value1 = 'N'
SET @Value1 = ''
ELSE
SET @Value1 = ' AND value1=' + '''' + @Value1 + ''''

SET @Sqlstr = 'SELECT a.Intime, c.Visitornm, c.Vcount, (CASE WHEN a.value2 = '+''''+''''+' THEN a.value1 + '+''''+''''+' WHEN a.value2 != '+''''+''''+' THEN a.value1 +'+ ''''+'-'+''''+' + a.value2 END) AS source0,
DATEDIFF(ms,a.Intime, a.Outtime) AS vtime, a.Pages, a.Rev1, dbo.GET_URL(a.SiteID, a.InURLID) AS inrul, dbo.GET_URL(a.SiteID, a.OutURLID) AS outrul
FROM dbo.F_Pages_T AS a INNER JOIN (SELECT VisitorID, MAX(ID) AS id FROM dbo.F_Pages_T WHERE SiteID = '+''''+CONVERT(VARCHAR,@siteid)+''''+ 'AND day0>= '+@startime+' AND day0<= ' +@endtime+@aflag0
+@area+ @Nflag0+ @Value1 +' GROUP BY VisitorID) AS b ON a.ID = b.id LEFT OUTER JOIN dbo.F_Visit AS c ON a.VisitorID = c.VisitorID'

PRINT @sqlstr
EXEC (@sqlstr)
END