regular expressions in transact sql

hi guys,

i need some help tp write code in order to search the string ( regular expressions) in t- sql.

e.g.

when a user enters [A-Z] it means any alphabet from 'A' to 'Z'...

similarly [0-9] means any digit.

the problem is: when user enters [0-6] and the string received contains digit 5 it should return true but if it contains 7 it should return false.

so how do i read the [A-Z] as a range of characters in t-sql?

hi,

In sql server it is not exactly regular expression, it is called wild card pattern. in other words it is simplified reqular expression,

as of now SQL Server Like operator only work with following operators

% - Zero or any number of chars

_ - Single Char

[] - Single Char in given range

- Single Char not in given range

if you want to utilize the exact regular expression on your query then the best solution will be CLR Functions.(SQL Server 2005).

For fixed validation (only numbers & only alphabets) i achived the following function,

Create Function dbo.IsMatching(@.Value as varchar(1000), @.Pattern as varchar(100))
returns bit as
Begin
Declare @.Len as int;
Declare @.SearchPattern as varchar(8000);
Declare @.Result as Int;

Select @.Len = Len(@.Value);

While @.Len>0
Begin
Select @.SearchPattern = Isnull(@.SearchPattern,'') + @.Pattern;
Select @.Len = @.Len -1;
End
Select @.Result = Case When @.Value Like @.SearchPattern Then 1 Else 0 End;
Return @.Result;
End

Go

select dbo.IsMatching('SQLServer','[A-Z]') as Result

Result : 1

select dbo.IsMatching('SQL Server','[A-Z]') as Result

Result : 0 --Space on String

select dbo.IsMatching('SQL Server','[A-Z ]') as Result

Result : 1 --Space added on Pattern

select dbo.IsMatching('12453','[1-5]') as Result

Result : 1

select dbo.IsMatching('12463','[1-5]') as Result

Result : 0

|||

thanks mani,

got the [A-Z] and [^a-z] concept.

my other requirements are to match zero or more characters and to match one or more characters.

e.g. T*he should match he, the, tthe, ttttthe.. etc.

and t+ho should match tho, thho, thhhhhhho, thhhhhhhhhhhhhho.. etc.

the above operators i have used in VC++,

do they work in t-sql too?

|||If you need regular expression and your platform is sqlserver 2005 you can use a CLR strored procedure. If you need help on this post a question on the .net framework inside sql server forum
http://forums.microsoft.com/MSDN/ShowForum.aspx?ForumID=86&SiteID=1|||

Yes.. if you want to find the repeated chars you can use the following condtions....

columnname not like '%aaa%'
and columnname not like '%bbb%'
and columnname not like '%ccc%'
and columnname not like '%ddd%'
and columnname not like '%eee%'
and columnname not like '%fff%'
and columnname not like '%ggg%'
and columnname not like '%hhh%'
and columnname not like '%iiii%'
and columnname not like '%jjj%'
and columnname not like '%kkk%'
and columnname not like '%lll%'
and columnname not like '%mmm%'
and columnname not like '%nnn%'
and columnname not like '%ooo%'
and columnname not like '%ppp%'
and columnname not like '%qqq%'
and columnname not like '%rrr%'
and columnname not like '%sss%'
and columnname not like '%ttt%'
and columnname not like '%uuu%'
and columnname not like '%vvv%'
and columnname not like '%www%'
and columnname not like '%xxx%'
and columnname not like '%yyy%'
and columnname not like '%zzz%'

http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=996813&SiteID=1

If you want to utilize the exact regular expression as i said earlier you can go for CLR Functions..