Re: [Pypgsql-users] Data type for oid

[Billy G. A. <bil...@de...>]

On Tue, 2005-08-30 at 16:44 +0000, Rod MacNeil wrote: 

> Hi All,
> 
> I'm using pyPgSQL 2.4 postgres 7.4.7 on fedora core 3.
> 
> I have a question about the data type returned in cursor.description when oid is included in the select.
> 
> When I run a query like "select oid, field1,field2 from mytable where field2='x'".
> 
> cursor.description says the oid column is type 'rowid' if there are result rows, but if there are no result rows it says the type is 'blob'.
> 
> Is this a bug?
> 
> Rod MacNeil

Not really.  It's caused by the fact that an OID can represent a rowid
or a postgresql large object (i.e. blob).  The only way to tell which
one it is is to see if the value of the OID exists as a large object or
not.  Since there is no result (and hence not value) the lookup can't be
made so a type of blob is assumed.
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