...
> 2) I set a 'European' DATESTYLE but the result is
> gedis30=# SET DATESTYLE to 'European';
> Help me for this problem
You need to set some date style other than "ISO" (which is the default).
Setting "European" affects output date ordering for those styles where
it would be noticable, and affects the interpretation of input dates,
but does not directly determine the style of the output.
Try
SET DATESTYLE = "Postgres,European";
or
SET DATESTYLE = "SQL,European";
for examples which may match what you want.
- Thomas