T-SQL IsNumeric() and Linq-to-SQL

Question

I need to find the highest value from the database that satisfies a certain formatting convention. Specifically, I would like to find the highest value that looks like

Answer 1

Although ISNUMERIC is missing, you could always try the nearly equivalent NOT LIKE '%[^0-9]%, i.e., there is no non-digit in the string, or alternatively, the string is empty or consists only of digits:

from x in table 
where SqlMethods.Like(x.col, 'EU[0-9]%') // starts with EU and at least one digit
  && !SqlMethods.Like(x.col, '__%[^0-9]%') // and no non-digits
select x;

Of course, if you know that the number of digits is fixed, this can be simplified to

from x in table 
where SqlMethods.Like(x.col, 'EU[0-9][0-9][0-9][0-9][0-9][0-9]')
select x;