IS it possible to use the 'Where' clause in SQL to only show a field containing only letters & Numbers?

Question

I want to be able to select only the field where a certain field contains both letters and numbers. for example:

Select [field1], [field2] 

from [db1].[tabl         


        

Answer 1

If you need it to contain both numerics and letters, and no other characters, I think you have to use 3 like clauses. One NOT LIKE, as @gbn said, then 2 LIKEs to ensure both character classes are represented:

select * from (select '123' union all select 'abc' union all select 'a2') t(Field)
where Field LIKE '%[0-9]%' and Field like '%[a-z]%'
AND Field NOT LIKE '%[^0-9a-z]%'

returns one row, with 'a2'.

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If it should only be letters followed by numbers, I'm thinking you might be able to achieve this with a further not like, again inspired by @gbn:

NOT LIKE '%[0-9]%[a-z]%'

But it is starting to look like a regex in CLR might be the preferred route.