Question

I’m building a hash, using the house number from an address field. What SQL can I use to select only the numeric characters from the front of a varchar field?

EX:

12345 South 1st Street

I want the 12345. Thanks in advance.

Answer 1

declare @MyColumn as varchar(250)
set @MyColumn = '12345 South 1st Street'
select @MyColumn, cast(left(@MyColumn, patindex('%[^0-9]%', @MyColumn)) as int)

If you do not know that there will be a number for sure, add a CASE statement as follows to prevent errors:

declare @MyColumn as varchar(250)
set @MyColumn = 'South 1st Street'
select @MyColumn as Address, case when patindex('%[^0-9]%', @MyColumn) = 1 then '' else left(@MyColumn, patindex('%[^0-9]%', @MyColumn)) end as StreetNumber

If there could be leading spaces, you may also want to add an LTRIM:

declare @MyColumn as varchar(250)
set @MyColumn = ' 12345 South 1st Street'
select @MyColumn as Address, case when patindex('%[^0-9]%', ltrim(@MyColumn)) = 1 then '' else left(ltrim(@MyColumn), patindex('%[^0-9]%', ltrim(@MyColumn))) end as StreetNumber