Retrieve N:N Relationship in Dynamics Crm - dynamics-crm-2011

Question

Currency entity is associated N:N Relationship with Lead.Now I'm trying to Retrieve associated Currency with the lead.i'm getting problem transaction currency does'nt contain attribute with leadid.could any references plz...
if (context.InputParameters.Contains("Target") && (context.InputParameters["Target"]) is Entity)
{
Entity en = (Entity)context.InputParameters["Target"];
QueryExpression _Query = new QueryExpression
{
EntityName = "transactioncurrency",
ColumnSet = new ColumnSet(true),
LinkEntities =
{
new LinkEntity
{
Columns=new ColumnSet(true),
LinkFromEntityName="lead",
LinkFromAttributeName="leadid",
LinkToEntityName="new_lead_transactioncurrency",
LinkToAttributeName="transactioncurrencyid",
LinkCriteria=new FilterExpression
{
FilterOperator=LogicalOperator.And,
Conditions=
{
new ConditionExpression
{
AttributeName="transactioncurrencyid",
Operator=ConditionOperator.Equal,
Values={ en.Id }
}
}
}
}
}
};
EntityCollection entitycollect = service.RetrieveMultiple(_Query);
int entitycount = entitycollect.Entities.Count;
}

Answer 1

I think you need to identify the correct LinkFromAttributeName and LinkToAttributeName.
QueryExpression query = new QueryExpression(entity1);
query.ColumnSet = new ColumnSet(true);
LinkEntity linkEntity1 = new LinkEntity("lead", "new_lead_transactioncurrency", "leadid", "leadid", JoinOperator.Inner);
LinkEntity linkEntity2 = new LinkEntity("new_lead_transactioncurrency", "transactioncurrency", "transactioncurrencyid", "transactioncurrencyid", JoinOperator.Inner);
linkEntity1.LinkEntities.Add(linkEntity2);
query.LinkEntities.Add(linkEntity1);
// Add condition to match the Bike name with “Honda”
linkEntity2.LinkCriteria = new FilterExpression();
linkEntity2.LinkCriteria.AddCondition(new ConditionExpression("raj_bikename", ConditionOperator.Equal, "Honda"));
EntityCollection collRecords = service.RetrieveMultiple(query);
For reference please have a look at the followng links:
Retrieve associated records (N:N related)
Sample: Convert queries between Fetch and QueryExpression