sqlserver 存储过程中拼接sql语句 动态执行

ALTER PROC [dbo].[Student_Friend_Get]
@startRowIndexId INT,
@maxNumberRows  INT,
@schoolId  INT,
@gradeId  INT,
@cId  INT,
@keyWords NVARCHAR(100),
@userName VARCHAR(50)
AS
BEGIN
DECLARE @sqlfilter  VARCHAR(max)
SET @sqlfilter = ' '
IF(@schoolId <> -1)
SET @sqlfilter = @sqlfilter + '   tableu.SchoolId =  ' + CAST(@schoolId AS VARCHAR(50)) + ' AND'
IF(@gradeId <> -1)
SET @sqlfilter =  @sqlfilter +  '  tableu.GradeId =  ' + CAST(@gradeId AS VARCHAR(50)) + ' AND'
IF(@cId <> -1)
SET @sqlfilter =  @sqlfilter +  '  tableu.ClassId =  ' + CAST(@cId AS VARCHAR(50)) + ' AND'
IF(@keyWords IS NOT NULL)
SET @sqlfilter =  @sqlfilter + '   tableu.TrueName like  ''%' + CAST(@keyWords AS VARCHAR(50))         + '%''  AND'

DECLARE @beg INT,@end INT
SET @beg =  @startRowIndexId+1
SET @end =  @startRowIndexId + @maxNumberRows
SET @sqlfilter = @sqlfilter +  '  tableu.num  BETWEEN  ' +CAST( @beg AS VARCHAR(50)) + ' AND '+ CAST(@end  AS VARCHAR(50))

DECLARE @sqlmain  VARCHAR(max)
SET @sqlmain = ' '
SET @sqlmain = @sqlmain  +  ' SELECT * FROM
(
SELECT ROW_NUMBER() OVER(ORDER BY cjs.UserName) AS num,CTA.TrueName, u.UserName, c.ClassName + '' (''+ CAST(YEAR(c.GradeUpdateTime) AS NVARCHAR(20))+''年)'' AS [ClassName],s.SchoolName,cjs.ApplyTime,g.GradeName,cjs.ApplyID,c.ClassId,g.GradeId,s.SchoolId
FROM PE_C_StudentJoinClass AS cjs
LEFT JOIN dbo.PE_SS_StudentClass AS c
ON cjs.ClassId = c.ClassId
LEFT JOIN dbo.PE_Users AS u
ON u.UserName = cjs.UserName
LEFT JOIN dbo.PE_SS_Grade g
ON g.GradeId = c.GradeId
LEFT JOIN dbo.PE_SS_School s
ON s.SchoolId = g.SchoolId
LEFT JOIN PE_Contacter CTA
ON cjs.UserName = CTA.UserName
WHERE ApplyID IN
(
SELECT
MAX(cs1.ApplyID) AS [ApplyID]
FROM PE_C_StudentJoinClass AS cs1
CROSS JOIN dbo.PE_C_StudentJoinClass AS cs2
WHERE cs2.UserName = '''+ CAST(@userName  AS VARCHAR(50))+ ''' AND cs1.UserName != ''' + CAST(@userName  AS VARCHAR(50))+  ''' AND cs1.ClassId = cs2.ClassId AND cs1.Status = 1
GROUP BY cs1.UserName
)
) AS tableu WHERE '

PRINT (@sqlmain + @sqlfilter)
EXEC (@sqlmain + @sqlfilter)

END

GO