Is it possible to pass a null parameter to a stored procedure in Java JPA 2.1?

Question

Using the new JPA 2.1 stored procedure call, is there any way to pass a null parameter?

Here is an example usage:

StoredProcedureQuery storedProcedur         


        

Answer 1

To go around the issue, if we dont have many possible null parameters to the sproc we can have multiple @NamedStoredProcedureQuery mapping to same sproc in DB. We can then prepare appropriate query.

For example,

  @NamedStoredProcedureQuery(name = "MyEntity.GetWithoutNullParam", procedureName = "dbo.GetProc", parameters = {
            @StoredProcedureParameter(mode = ParameterMode.IN, name = "id", type = Integer.class)},
            resultClasses = MyEntity.class),
    @NamedStoredProcedureQuery(name = "MyEntity.GetWithNullParam", procedureName = "dbo.GetProc", parameters = {
            @StoredProcedureParameter(mode = ParameterMode.IN, name = "id", type = Integer.class),
            @StoredProcedureParameter(mode = ParameterMode.IN, name = "nullableparam", type = String.class), 
resultClasses = MyEntity.class)

Now doing a null check on "nullableparam" we can create appropriate named proc in repository. Something similar to

if(MyEntity.nullableparam == null){StoredProcedureQuery storedProcedureQuery = em.createNamedStoredProcedureQuery("MyEntity.GetWithoutNullParam");}
else{StoredProcedureQuery storedProcedureQuery = em.createNamedStoredProcedureQuery("MyEntity.GetWithNullParam");}