Question

How can I gracefully handle bad date integers that are random thorughout my table? For instance I see some 9999999999 in there at times so consequently this query bombs out. I want to just produce the 1900 date in those cases instead of just stopping like this:

Select convert(date,CAST(trandate as varchar(8))),
       convert(date,CAST(duedate as varchar(8))), 
        ...

FROM  SomeTable

a valid date looks like this in that table for those fields: 20100924 and those work fine when they hit this query.

Answer 1

You can use the isdate built-in function in sql server to check if something is castable to a date and then handle it however.

Example:

declare @mytable table (thedate varchar(20))
insert into @mytable values ('20100924')
insert into @mytable values ('99999')

select 
case when isdate(thedate)=1 then
    CAST(thedate as datetime)
else null end as foo
from @mytable