[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [List Home]
Re: [eclipselink-users] Which dynamic type to query?

Hello Rohit,

The query.addJoinedAttribute(String) is a convenience method that turns into query.addJoinedAttribute(query.getExpressionBuilder().get(String));
Since your "id1" string represents a OneToMany, it needs to use anyOf instead of get as the exception states. 

Best Regards,
Chris




On 08/12/2010 12:15 PM, Rohit Banga wrote:
OK
I will try that once I am back on my development machine. Could you please explain the rationale behind this?

Thanks

Member Technical Staff 
Oracle India Private Limited 
91 80 41085685 

----- Original Message -----
From: jamesssss@xxxxxxxxx
To: eclipselink-users@xxxxxxxxxxx
Sent: Wednesday, December 8, 2010 9:59:25 PM GMT +05:30 Chennai, Kolkata, Mumbai, New Delhi
Subject: Re: [eclipselink-users] Which dynamic type to query?


Use,
query.addJoinedAttribute(query.getExpressionBuilder().anyOf("id1"));


Rohit Banga-2 wrote:
  
  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

_______________________________________________
eclipselink-users mailing list
eclipselink-users@xxxxxxxxxxx
https://dev.eclipse.org/mailman/listinfo/eclipselink-users


    


-----
http://wiki.eclipse.org/User:James.sutherland.oracle.com James Sutherland 
http://www.eclipse.org/eclipselink/
 EclipseLink ,  http://www.oracle.com/technology/products/ias/toplink/
TopLink 
Wiki:  http://wiki.eclipse.org/EclipseLink EclipseLink , 
http://wiki.oracle.com/page/TopLink TopLink 
Forums:  http://forums.oracle.com/forums/forum.jspa?forumID=48 TopLink , 
http://www.nabble.com/EclipseLink-f26430.html EclipseLink 
Book:  http://en.wikibooks.org/wiki/Java_Persistence Java Persistence 
Blog:  http://java-persistence-performance.blogspot.com/ Java Persistence
Performance