While using Dynamic Query getting "QueryException: could not resolve property"

Here is the solution.......

DynamicQuery dynaQuery = DynamicQueryFactoryUtil
                .forClass(User_Customer.class);

dynaQuery.setProjection(ProjectionFactoryUtil
.property("primaryKey.id_customer");

dynaQuery.add(RestrictionsFactoryUtil.eq("primaryKey.id_userId", userId));

List<Integer> customerIds = new ArrayList<Integer>();
customerIds = (List<Integer>)user_CustomerPersistence.findWithDynamicQuery(dynaQuery);

The case is...you have a composite key and whenever you try using it like this

dynaQuery.setProjection(ProjectionFactoryUtil.property("id_customer");

You are getting an exception, something like this:-

06:34:05,450 ERROR [http-bio-8080-exec-88][BasePersistenceImpl:186] 

Caught unexpected exception org.hibernate.QueryException
com.liferay.portal.kernel.exception.SystemException: 

org.hibernate.QueryException: could not resolve property: userId of:

com.test.model.impl.User_CustomerImpl

Use "primaryKey.columnName" instead of "columnName"