| [eclipselink-users] Which dynamic type to query? |
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Hello All I am currently experimenting with eclipselink dynamic persistence: http://wiki.eclipse.org/EclipseLink/Development/JPA/Dynamic I am creating an Employee and a Department class with a One-To-Many mapping from the department to employee tables using the following code: departmentTypeBuilder.addOneToManyMapping("id1", employeeTypeBuilder.getType(), "empinfo.depid"); employeeTypeBuilder.addOneToOneMapping("id1", departmentTypeBuilder.getType(), "empinfo.depid"); This is based on the explanation at the following page: http://wiki.eclipse.org/Introduction_to_Relational_Mappings_(ELUG) After this I add both the types as follows: helper.addTypes(false, true, departmentTypeBuilder.getType(), employeeTypeBuilder.getType()); helper.addTypes(false, true, employeeTypeBuilder.getType(), departmentTypeBuilder.getType()); // helper.addTypes(false, false, employeeTypeBuilder.getType()); // also works, but don't know why? which one is correct? After this I create a ReadAllQuery: ReadAllQuery query = new DynamicHelper(session).newReadAllQuery(employeeTypeBuilder.getType().getDescriptor().getAlias()); query.addJoinedAttribute("id1"); query.prepareCall(session, new DatabaseRecord()); The above code works. However if I create a query using "departmentTypeBuilder.getType().getDescriptor().getAlias()", I get the following exception: Exception Description: Invalid use of a query key [org.eclipse.persistence.mappings.OneToManyMapping[id1]] representing a "to-many" relationship in an _expression_. Use anyOf() rather than get(). at org.eclipse.persistence.exceptions.QueryException.invalidUseOfToManyQueryKeyInExpression(QueryException.java:735) at org.eclipse.persistence.internal.expressions.QueryKeyExpression.validateNode(QueryKeyExpression.java:887) at org.eclipse.persistence.expressions._expression_.normalize(_expression_.java:3009) at org.eclipse.persistence.internal.expressions.DataExpression.normalize(DataExpression.java:342) ... Can you please tell me why this fails? Are there any rules regarding which DynamicType to query for various type of mappings possible between tables? Thanks in Advance. --
Thanks and Regards Rohit Banga Software Developer Oracle Server Technologies |