| Re: [eclipselink-users] Order of adding Join Attribute Expressions when using Dynamic Persistence |
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Hello All I am responding to an earlier unanswered mail thread that I had started on a query that is similar to the one asked before. In order to shed more light on the issue, I have included a more specific example in this mail. I have attached a program to give you an idea of where I am facing a problem. Each type corresponds to a table in the database. I have the following questions: 1. I am querying customer type for all orders placed by her. Each order has a corresponding invoice. However when I query the order dynamic type for the join attribute invoice9.order9.invoiceid then I do not get any invoices. Moreover the type of e2 is IndirectList. If I do not add the exp4 join attribute then I do get the invoice corresponding to the order (List e2 is not empty). Why is this happening? 2. If I use setUsesIndirection to false for all the mappings, the first entity does not have any invoices as above however for all other entities I get a Vector instead of an IndirectList which has the expected objects of the dynamic type invoice. In this case the number of accesses to the database is also large. Could you please explain the behavior? -- Thanks and Regards
Rohit Banga Member Technical Staff Oracle Server Technologies On 12/20/2010 10:21 AM, Rohit Banga wrote: Hi Christopher --
Thanks and Regards Rohit Banga Member Technical Staff Oracle Server Technologies |
import java.util.List;
import org.eclipse.persistence.dynamic.DynamicClassLoader;
import org.eclipse.persistence.dynamic.DynamicEntity;
import org.eclipse.persistence.dynamic.DynamicHelper;
import org.eclipse.persistence.dynamic.DynamicTypeBuilder;
import org.eclipse.persistence.expressions.Expression;
import org.eclipse.persistence.expressions.ExpressionBuilder;
import org.eclipse.persistence.internal.sessions.DatabaseSessionImpl;
import org.eclipse.persistence.jpa.dynamic.JPADynamicTypeBuilder;
import org.eclipse.persistence.queries.ReadAllQuery;
import org.eclipse.persistence.sessions.DatabaseLogin;
import org.eclipse.persistence.sessions.DatabaseRecord;
import org.eclipse.persistence.sessions.DatabaseSession;
/**
* @author rbanga
*
*/
public class JoinOrderProblem {
@SuppressWarnings("unchecked")
public static void main(String[] args)
{
DatabaseLogin login = new DatabaseLogin();
login.setUserName("******");
login.setPassword("******");
login.setDriverURLHeader("******");
login.setDriverClassName("******");
login.setDatabaseURL("**************");
DatabaseSession session = new DatabaseSessionImpl(login);
session.login();
DynamicHelper helper = new DynamicHelper(session);
DynamicClassLoader dcl = helper.getDynamicClassLoader();
Class<?> custType = dcl.createDynamicClass("jpatest.customer");
Class<?> invoiceType = dcl.createDynamicClass("jpatest.invoice");
Class<?> orderType = dcl.createDynamicClass("jpatest.order");
Class<?> bookType = dcl.createDynamicClass("jpatest.book");
Class<?> orderBookType = dcl.createDynamicClass("jpatest.orderbook");
DynamicTypeBuilder custBuilder = new JPADynamicTypeBuilder(custType, null, "cust9");
custBuilder.setPrimaryKeyFields("custid");
custBuilder.addDirectMapping("custid", int.class, "custid");
custBuilder.addDirectMapping("name", String.class, "name");
DynamicTypeBuilder invoiceBuilder = new JPADynamicTypeBuilder(invoiceType, null, "invoice9");
invoiceBuilder.setPrimaryKeyFields("invoiceid");
invoiceBuilder.addDirectMapping("invoiceid", int.class, "invoiceid");
invoiceBuilder.addDirectMapping("value", int.class, "value");
DynamicTypeBuilder orderBuilder = new JPADynamicTypeBuilder(orderType, null, "order9");
orderBuilder.setPrimaryKeyFields("orderid");
orderBuilder.addDirectMapping("orderid", int.class, "orderid");
orderBuilder.addDirectMapping("qty", int.class, "qty");
DynamicTypeBuilder bookBuilder = new JPADynamicTypeBuilder(bookType, null, "book9");
bookBuilder.setPrimaryKeyFields("bookid");
bookBuilder.addDirectMapping("bookid", int.class, "bookid");
bookBuilder.addDirectMapping("title", String.class, "name");
DynamicTypeBuilder orderBookBuilder = new JPADynamicTypeBuilder(orderBookType, null, "order9_book9");
orderBookBuilder.setPrimaryKeyFields("bookid", "orderid");
custBuilder.addOneToManyMapping("cust9.order9.custid", orderBuilder.getType(), "order9.custid");
orderBuilder.addOneToOneMapping("cust9.order9.custid", custBuilder.getType(), "order9.custid");
orderBuilder.addOneToManyMapping("invoice9.order9.invoiceid", invoiceBuilder.getType(), "invoice9.orderid");
invoiceBuilder.addOneToOneMapping("invoice9.order9.invoiceid", orderBuilder.getType(), "invoice9.orderid");
orderBuilder.addOneToManyMapping("order9.order9_book9.orderid", orderBookBuilder.getType(), "order9_book9.orderid");
orderBookBuilder.addOneToOneMapping("order9.order9_book9.orderid", orderBuilder.getType(), "order9_book9.orderid");
bookBuilder.addOneToManyMapping("book9.order9_book9.bookid", orderBookBuilder.getType(), "order9_book9.bookid");
orderBookBuilder.addOneToOneMapping("book9.order9_book9.bookid", bookBuilder.getType(), "order9_book9.bookid");
helper.addTypes(false, true, custBuilder.getType(),
orderBuilder.getType(), invoiceBuilder.getType(),
bookBuilder.getType(), orderBookBuilder.getType()
);
ReadAllQuery query = helper.newReadAllQuery(custBuilder.getType().getDescriptor().getAlias());
Expression exp1 = new ExpressionBuilder().anyOf("cust9.order9.custid");
Expression exp2 = new ExpressionBuilder().anyOf("cust9.order9.custid").anyOf("order9.order9_book9.orderid");
Expression exp3 = new ExpressionBuilder().anyOf("cust9.order9.custid").anyOf("invoice9.order9.invoiceid");
Expression exp4 = new ExpressionBuilder().anyOf("cust9.order9.custid").anyOf("order9.order9_book9.orderid").get("book9.order9_book9.bookid");
query.addJoinedAttribute(exp1);
query.addJoinedAttribute(exp2);
query.addJoinedAttribute(exp3);
query.addJoinedAttribute(exp4);
query.prepareCall(session, new DatabaseRecord());
System.out.println("query: " + query.getSQLString());
for (DynamicEntity entity : (List<DynamicEntity>) session.executeQuery(query))
{
System.out.println("custid:" + entity.get("custid"));
System.out.println("name:" + entity.get("name"));
for (DynamicEntity e1 : (List<DynamicEntity>) entity.get("cust9.order9.custid"))
{
System.out.println("orderid: " + e1.get("orderid") );
System.out.println("qty: " + e1.get("qty") );
System.out.println(e1.get("invoice9.order9.invoiceid").getClass().getName());
List<DynamicEntity> e2 = (List<DynamicEntity>) e1.get("invoice9.order9.invoiceid");
System.out.println("number of entities: " + e2.size());
for (DynamicEntity e3 : e2)
{
System.out.println("invoiceid: " + e3.get("invoiceid") );
System.out.println("value: " + e3.get("value") );
}
}
System.out.println();
}
}
}