Question

I have a constructor criteria query. For the constructor, I’m attempting to do something like this:

query.select( builder.construct( MyView.class
    , metaObject
    , builder.selectCase( builder.isNull( metaOtherObject )).when( true, null ).otherwise( metaOtherObject.get( MetaOtherObject_.myDateField ))
));

If I use when(true,null) then I get a NullPointerException on that line. If I use something like when(true,new Date()) then it looks alright. Problem is, I need to be able to pass a null in there if the OtherObject wasn’t found. How can I do that?

I’m using eclipselink as the provider hitting postgres.

Answer 1

Looks like I need to use the CriteriaBuilder literal or nullLiteral methods. Something like

Expression nil = builder.literal(null);
// or
Expression<Date> nilDate = builder.nullLiteral(Date.class);
// then I can 
blah.when(true, nilDate).otherwise(blah)

While my query still fails, it isn’t in the constructor portion where I was trying to use just null directly. I believe the other problems are unrelated to this.