Error: Query projections cannot include array, collection, or map fields

[Virag Kothari]

Hi All,

I am facing the following exception when having a blob (byte[]) as part of 
select statement.

Caused by: <openjpa-2.2.2-r422266:1468616 nonfatal user error> 
org.apache.openjpa.persistence.ArgumentException: Query projections cannot 
include array, collection, or map fields.  Invalid query: "select  a.lob1 from 
DummyBean a"

The following are the relevant parts of DummyBean:


@NamedQuery(name = "GET_LOB1", query = "select  a.lob1 from DummyBean a"),


    @Column(name = "lob1")

    @Lob

    private byte[] lob1 = null;



Is there a way to selectively retrieve just the byte[] (blob) columns? I know 
that "select OBJECT(a) from …" would work.

Without using JPA, I can prepare the statement using java.sql.Statement and 
retrieve using ResultSet.getByteArray(). What should I do to make it work with 
JPA?


Appreciate any help.


Thanks,

Virag