Postgres 8.0 hibernate3.1.3
1. Need help with HQL query to display the date after 30 days from todays date ?.

2. If anyone knows a good link for HQL.could you please tell.

Looks like the postgres dialect doesn't have a dateadd function. Does postgres? If it does, and if you're willing to recompile your hibernate jar, you could registerFunction whatever the dateadd function postgres provides, then use it in HQL.

Have a look in PostgreSQLDialect.java. Add a registerFunction in where all the others are.

If postgres doesn't have a function that adds to dates, then there's not much you can do. You could use the year(), month() etc. functions, but there's a lot of work figuring out month and year changes, leap years, etc. Might as well just do it in java, it's easy enough with Calendar objects.

(CURRENT DATE + (Integer + '30') )will add 30 days to the current date in postgres.

I have to retrieve all records from database with date less than (CURRENT DATE + (Integer + '30') ).

Is there a way to get this using HQL

current_date is in the dialect. Don't know about integer part, can you use "current_date + 30", omitting the single quotes and Integer thing?

You can see exactly what functions are already provided by the dialect by looking in the dialect file, org/hibernate/dialect/PostgreSQLDialect.java.