How to perform date operations in hibernate

Question

I want to perform data time operations using hibernate HQL.

I want to add and subtract two dates as well as I want to subtract 1 year or 1 month from a particular date.

How is this possible using HQL in hibernate?

Answer 1

See Performing Date/Time Math In HQL? for an example.

To use custom sql you must wrote an own hibernate dialect and register:

registerFunction("weekday", 
  new SQLFunctionTemplate(Hibernate.INTEGER, "to_char(?1,'D')") );

Answer 2

You need to create your own dialect. Something like the following:

public class MyDialect extends MySQLInnoDBDialect{
      public MyDialect() {
      super();
      registerFunction("date_add_interval", new SQLFunctionTemplate(Hibernate.DATE, "date_add(?1, INTERVAL ?2 ?3)"));
      }
    }