Question

I have the code:

@Id
@Column(name = "id")
@GeneratedValue
private int id;

@Formula(value = "(SELECT count(history.city_id) FROM history where history.ts > (now() - INTERVAL 30 DAY) and history.city_id = id)")
private int last30daysUpdates;

so, hiberante parse this formula to:

 ...where
            history.ts > (
                now() - entitycity0_.INTERVAL 30 entitycity0_.DAY
            ) ...

and the error is:

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ’30 entitycity0_.DAY)

How can i say hibernate that INTERVAL and DAY are the functions of MysqL? Is it possible?

Thanks.

Answer 1

Which MySQL dialect are you use?
If MySqlDialect oder MySql5Dialect you can use follows:

SELECT count(history.city_id) FROM history where timediff(now(), history.ts) < '720' and history.city_id = id

Or define new hibernate function

public class ExtendedMySQL5Dialect extends MySQL5Dialect 
{
        public ExtendedMySQL5Dialect() 
        {
           super();
           registerFunction( "date_sub_interval", new SQLFunctionTemplate( Hibernate.DATE, "date_sub(?1, INTERVAL ?2 ?3)" ) );
           registerFunction( "date_add_interval", new SQLFunctionTemplate( Hibernate.DATE, "date_add(?1, INTERVAL ?2 ?3)" ) );           
        }
}

Query:

History.ts < date_sub_interval(now(), 30, DAY)