关于存储过程可空条件查询
大家都知道使用存储过程的好处其中有2点
1、参数查询安全(用参数就安全?)
2、存储过程在创建时预编译,执行效率比SQL语句要高
基于这两点,看看下面这段以前经常写的存储过程吧(查询数据)
CREATE PROCEDURE [dbo].[usp_TestExec] @Account VARCHAR(50)='', @UserName VARCHAR(50)='' AS BEGIN DECLARE @SQL VARCHAR(8000) SET @SQL='SELECT * FROM dbo.tb_Test WHERE 1=1'; IF(ISNULL(@Account,'')<>'') SET @SQL=@SQL+' AND Account LIKE ''%'+@Account+'%''' IF(ISNULL(@UserName,'')<>'') SET @SQL=@SQL+' AND UserName LIKE ''%'+@UserName+'%''' EXEC(@SQL) END
运行,测试没问题。
可是有谁会考虑到注入?
看着存储过程我觉得有两个问题
1.实际还是运行SQL,如果条件不一样,生成的SQL语句不一样,预编译运行成为美丽的谎言
2.不能够预防SQL代码注入,不相信请(测)看(试)
运行如下代码会出现何种结果?
EXEC usp_TestExec "fdsgdsgsdd' OR '' LIKE '"
出问题咯,作为一个有进取心的程序员,此时是不是听到一句话:该重写了
这里是我的方法:
ALTER PROCEDURE [dbo].[usp_TestExec] @Account VARCHAR(50)='', @UserName VARCHAR(50)='' AS BEGIN --usp_TestExec "DB' OR '' LIKE '" --usp_TestExec 'DB' DECLARE @SQL VARCHAR(8000) SELECT * FROM dbo.tb_Test WHERE ((@Account IS NULL AND Account IS NULL) OR @Account='' OR (Account LIKE '%'+@Account+'%')) AND ((@UserName IS NULL AND UserName IS NULL) OR @UserName='' OR (UserName LIKE '%'+@UserName+'%')) END
运行测试一下:
exec usp_TestExec "DB' OR '' LIKE '"
exec usp_TestExec 'DB'
注入问题解决,而且由于没有拼接SQL语句,可以说这样的存储过程才预编译后执行查询的。
应该还有其他方法。
附上一段SqlCommandBuilder生成的Update语句,给看得懂的人看吧:
UPDATE [dbo].[tb_TT] SET [FRbigint] = @FRbigint , [Fbinary] = @Fbinary , [Fbit] = @Fbit , [Fchar] = @Fchar , [Fdate] = @Fdate , [Fdatetime] = @Fdatetime , [Fdatetime2] = @Fdatetime2 , [Fdatetimeoffset] = @Fdatetimeoffset , [Fdecimal] = @Fdecimal , [Ffloat] = @Ffloat , [Fgeography] = @Fgeography , [Fgeometry] = @Fgeometry , [Fhierarchyid] = @Fhierarchyid , [Fimage] = @Fimage , [Fint] = @Fint , [Fmoney] = @Fmoney , [Fnchar] = @Fnchar , [Fntext] = @Fntext , [Fnumeric] = @Fnumeric , [Fnvarchar] = @Fnvarchar , [FnvarcharMax] = @FnvarcharMax , [Freal] = @Freal , [Fsmalldatetime] = @Fsmalldatetime , [Fsmallint] = @Fsmallint , [Fsmallmoney] = @Fsmallmoney , [Fsql_variant] = @Fsql_variant , [Ftext] = @Ftext , [Ftime] = @Ftime , [Ftinyint] = @Ftinyint , [Funiqueidentifier] = @Funiqueidentifier , [Fvarbinary] = @Fvarbinary , [Fvarbinary_Max] = @Fvarbinary_Max , [Fvarchar] = @Fvarchar , [Fvarchar_Max] = @Fvarchar_Max , [Fxml] = @Fxml WHERE ( ([isid] = @Original_isid) AND ((@IsNull_FRbigint = 1 AND [FRbigint] IS NULL) OR ([FRbigint] = @Original_FRbigint)) AND ((@IsNull_Fbinary = 1 AND [Fbinary] IS NULL) OR ([Fbinary] = @Original_Fbinary)) AND ((@IsNull_Fbit = 1 AND [Fbit] IS NULL) OR ([Fbit] = @Original_Fbit)) AND ((@IsNull_Fchar = 1 AND [Fchar] IS NULL) OR ([Fchar] = @Original_Fchar)) AND ((@IsNull_Fdate = 1 AND [Fdate] IS NULL) OR ([Fdate] = @Original_Fdate)) AND ((@IsNull_Fdatetime = 1 AND [Fdatetime] IS NULL) OR ([Fdatetime] = @Original_Fdatetime)) AND ((@IsNull_Fdatetime2 = 1 AND [Fdatetime2] IS NULL) OR ([Fdatetime2] = @Original_Fdatetime2)) AND ((@IsNull_Fdatetimeoffset = 1 AND [Fdatetimeoffset] IS NULL) OR ([Fdatetimeoffset] = @Original_Fdatetimeoffset)) AND ((@IsNull_Fdecimal = 1 AND [Fdecimal] IS NULL) OR ([Fdecimal] = @Original_Fdecimal)) AND ((@IsNull_Ffloat = 1 AND [Ffloat] IS NULL) OR ([Ffloat] = @Original_Ffloat)) AND ((@IsNull_Fhierarchyid = 1 AND [Fhierarchyid] IS NULL) OR ([Fhierarchyid] = @Original_Fhierarchyid)) AND ((@IsNull_Fint = 1 AND [Fint] IS NULL) OR ([Fint] = @Original_Fint)) AND ((@IsNull_Fmoney = 1 AND [Fmoney] IS NULL) OR ([Fmoney] = @Original_Fmoney)) AND ((@IsNull_Fnchar = 1 AND [Fnchar] IS NULL) OR ([Fnchar] = @Original_Fnchar)) AND ((@IsNull_Fnumeric = 1 AND [Fnumeric] IS NULL) OR ([Fnumeric] = @Original_Fnumeric)) AND ((@IsNull_Fnvarchar = 1 AND [Fnvarchar] IS NULL) OR ([Fnvarchar] = @Original_Fnvarchar)) AND ((@IsNull_Freal = 1 AND [Freal] IS NULL) OR ([Freal] = @Original_Freal)) AND ((@IsNull_Fsmalldatetime = 1 AND [Fsmalldatetime] IS NULL) OR ([Fsmalldatetime] = @Original_Fsmalldatetime)) AND ((@IsNull_Fsmallint = 1 AND [Fsmallint] IS NULL) OR ([Fsmallint] = @Original_Fsmallint)) AND ((@IsNull_Fsmallmoney = 1 AND [Fsmallmoney] IS NULL) OR ([Fsmallmoney] = @Original_Fsmallmoney)) AND ((@IsNull_Fsql_variant = 1 AND [Fsql_variant] IS NULL) OR ([Fsql_variant] = @Original_Fsql_variant)) AND ((@IsNull_Ftime = 1 AND [Ftime] IS NULL) OR ([Ftime] = @Original_Ftime)) AND ((@IsNull_Ftinyint = 1 AND [Ftinyint] IS NULL) OR ([Ftinyint] = @Original_Ftinyint)) AND ((@IsNull_Funiqueidentifier = 1 AND [Funiqueidentifier] IS NULL) OR ([Funiqueidentifier] = @Original_Funiqueidentifier)) AND ((@IsNull_Fvarbinary = 1 AND [Fvarbinary] IS NULL) OR ([Fvarbinary] = @Original_Fvarbinary)) AND ((@IsNull_Fvarchar = 1 AND [Fvarchar] IS NULL) OR ([Fvarchar] = @Original_Fvarchar)))
慎于行,敏于思!GGGGGG