The JPA spec actually says the function invocation syntax can be used for database functions in 4.6.17.3.
By "supported" you mean something like a note that says JPA providers may allow the invocation of JPA provider specific functions via that syntax? I'd love to go even further and standardize the definition of functions, but I guess that's not going to happen, so this seems to be a good compromise/first step. Mit freundlichen Grüßen, ------------------------------------------------------------------------ *Christian Beikov* Am 24.04.2018 um 15:21 schrieb Gail Badner: > Yes, that should work with CriteriaQuery as well. It's a reasonable > workaround. > > If JPA doesn't support this now, is it something that should be > supported in the future? > > On Mon, Apr 23, 2018 at 11:45 PM, Christian Beikov > <christian.bei...@gmail.com <mailto:christian.bei...@gmail.com>> wrote: > > Hey Gail, > > I usually register a dedicated SQLFunction for every time value in > the > Dialect and use these functions instead. So in your case, I'd have a > "day" function and use it like > > final Expression<Integer> diff = cb.function("DAY", Integer.class, > ... ).as(Integer.class); > > The fuction will then render the SQL like it is supposed to be > > "select datediff( day, ... ) from ..." > > Although I'm not 100% sure that CriteriaBuilder.function properly > resolves the function since I never used custom function with the JPA > Criteria API directly, I'd at least expect it. > > Mit freundlichen Grüßen, > ------------------------------------------------------------------------ > *Christian Beikov* > Am 24.04.2018 um 07:29 schrieb Gail Badner: > > SQL Server defines a function: > > > > DATEDIFF ( datepart , startdate , enddate ) [1] > > > > (This method still needs to be added to SQLServer2012Dialect.) > > > > datepart can be one of a variety of time values, e.g., day, > week, year, etc. > > > > On SQL Server (at least) the value for datepart cannot be > treated as a > > literal (enclosed in quotes) or bound as a parameter. > > > > This causes problems when using DATEDIFF in a CriteriaQuery. > > > > final Expression<Integer> diff = cb.function("DATEDIFF", > Integer.class, > > cb.literal("day"), ... ).as(Integer.class); > > > > SQL Server throws: > > com.microsoft.sqlserver.jdbc.SQLServerException: Invalid parameter 1 > > specified for datediff. > > > > There is no problem using the function in a query, as long as > datepart is > > not enclosed in quotes or bound to the query: > > > > "select datediff( day, ... ) from ..." > > > > Is there some way to set a literal value using a CriteriaQuery > that will > > not ultimately be enclosed in quotes or bound to a query? > > > > I've also been trying to find an integer constant that would be > equivalent > > to 'day', but haven't had any luck. > > > > Anyone have an idea how this could be done with CriteriaQuery? > > > > Thanks, > > Gail > > > > [1] > > > > https://docs.microsoft.com/en-us/sql/t-sql/functions/datediff-transact-sql?view=sql-server-2017 > > <https://docs.microsoft.com/en-us/sql/t-sql/functions/datediff-transact-sql?view=sql-server-2017> > > _______________________________________________ > > hibernate-dev mailing list > > hibernate-dev@lists.jboss.org <mailto:hibernate-dev@lists.jboss.org> > > https://lists.jboss.org/mailman/listinfo/hibernate-dev > <https://lists.jboss.org/mailman/listinfo/hibernate-dev> > > _______________________________________________ > hibernate-dev mailing list > hibernate-dev@lists.jboss.org <mailto:hibernate-dev@lists.jboss.org> > https://lists.jboss.org/mailman/listinfo/hibernate-dev > <https://lists.jboss.org/mailman/listinfo/hibernate-dev> > > _______________________________________________ hibernate-dev mailing list hibernate-dev@lists.jboss.org https://lists.jboss.org/mailman/listinfo/hibernate-dev
