Question

I am trying to retrieve the largest number from a varchar column that includes both numbers and strings. An example of the data I’m working with:

BoxNumber
123
A5
789
B1

I need to return the largest number (789 in this case) from the column while ignoring the non-numeric values of A5 and B1.

I have found solutions that use custom functions to solve the problem, but I need something that can be executed ad-hoc query without relying on custom functions or procs.

Answer 1

you need a combination because of the fact that isnumeric returns 1 for the following things

select isnumeric('+'),isnumeric('5d2')  

your where clause would be like this

WHERE VALUE NOT LIKE '%[a-z]%'         AND ISNUMERIC(VALUE) = 1  create table #bla (value varchar(50)) insert #bla values('123') insert #bla values('a5') insert #bla values('789') insert #bla values('b1')  SELECT MAX(CAST(value AS Int)) FROM #bla WHERE VALUE NOT LIKE '%[a-z]%'     AND ISNUMERIC(VALUE) = 1 

I wrote about this here ISNUMERIC Trouble