Complex HQL Query

[Bai Shen]

Okay, so I have the following classes.

Class A (abstract class)
 ID
 Name

Class B (subclass of A)
 Prop 1
 Prop 2
 Prop 3

Class C (subclass of A)
 Prop 4
 Prop 5
 Prop 6
 One-To-Many with Class B

Now I'm trying to write a query in order to select prop 3, prop 4, and whether or not there is a link between C and B(I don't need Class B, just whether it's null or not). I have the Name of Class C. I currently have a query like this.

select prop4,prop5,classB from ClassC where Name = 'name'

But this returns the following error. Not sure why it changes the case, either.

ERROR: column reference "name" is ambiguous

I have it working with a Criteria, but I'd like to do it this way because I don't need the whole object.

Thanks.

[afsar khan]

Dear Ranch Hand,

If you use Criteria Than also you do not need to get the whole object if you are creating a Criterai Query and by using Projection Class you can get the required properties also.

Here is a simple way to get the results as List of object array containing the name property.

List results = session.createCriteria(A.class)
.setProjection( Projections.projectionList()
.add( Projections.property("name"), "Name" )
)
.add( Restrictions.eq("Name", "Your_Condition") )

Hope this will help you...

[Bai Shen]

afsar khan wrote:Dear Ranch Hand,

If you use Criteria Than also you do not need to get the whole object if you are creating a Criterai Query and by using Projection Class you can get the required properties also.

Here is a simple way to get the results as List of object array containing the name property.

List results = session.createCriteria(A.class)
.setProjection( Projections.projectionList()
.add( Projections.property("name"), "Name" )
)
.add( Restrictions.eq("Name", "Your_Condition") )

Hope this will help you...

Didn't know about the Projection class. I'll have to take a look.