Bill,
> I am a newbie to postgreSQL, is it possible to write a "DateDiff",
> "IsNull" function work same as the one in SQL Server and are there
> and
> sample out there?
I take it that you want to do this to port an exisiting application?
If so, the DateDiff thing has already been covered in Roberto Mello's
"cookbook".
However, ISNULL, last I checked, was a Microsoft Access function and not
supported by MS SQL Server. If you're porting from MS Access, you'll
need to fix a lot more of your SQL than the functions. There is,
however, help for MS Access users:
(for both of the above)
http://techdocs.postgresql.org/
> And is it possible to override the existing
> function and
> operator like "+" to become a concate?
How's your C porgramming? It's an open-source database, you can do
anything for which you have the skill and the time. The advisability of
doing so, however, is another thing entirely ...
Given that all of the MS SQL Server "peculiarities" are not ANSI SQL
standard, have you given any thought to porting by search-and-replace
script instead of trying to make Postgres support a bunch of
non-standard operators and functions? It'd be easier.
-Josh Berkus
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