SQL Server, where field is int?

Question

how can I accomplish:

select * from table where column_value is int

I know I can probably inner join to the system tables and type tables b

Answer 1

If you are purely looking to verify a string is all digits and not just CAST-able to INT you can do this terrible, terrible thing:

select LEN(
 REPLACE( REPLACE( REPLACE( REPLACE( REPLACE( REPLACE( REPLACE( REPLACE( REPLACE( REPLACE(
 '-1.223344556677889900e-1'
 ,'0','') ,'1','') ,'2','') ,'3','') ,'4','') ,'5','') ,'6','') ,'7','') ,'8','') ,'9','')
)

It returns 0 when the string was empty or pure digits.

To make it a useful check for "poor-man's" Integer you'd have to deal with empty string, and an initial negative sign. And manually make sure it isn't too long for your variety of INTEGER.