>>Is it possible to subtract 2 dates in ANSI SQL92 and get a number of days, months, or years? What is the syntax?
>
>Cindy,
>
>I've not been able to locate any kind of documentation about pure ANSI SQL. If you find something, please forward it to me.
>
>Try using DATEDIFF(part, startdate, enddate). I'm not sure if it's specific to SQL Server or not.
>
>WHERE DATEDIFF(year, dDOB, dDischargeDate) > 18
>
>I'm not making any promises...
>
>-Mike

DATEDIFF is a no-go for ANSI SQL.

I have an interesting book where a lot of SQL functions from various platforms are listed, and DATEDIFF is not listed!

(Wayne S. Freeze, SQL Programmers Reference)