Fetching one to many relation values using NSPredicate

Question

I have core data model with entities department and employees with to-many relationship from department to employee (department-->> employee).I need to fetch all the departments with employees joining date between two dates.

How to Set the predicate for this ???

Thank You....

Answer 1

I think you need a SUBQUERY here:

[NSPredicate predicateWithFormat:@"SUBQUERY(employees, $e, $e.joinDate >= %@ AND $e.jointDate >= %@).@count > 0",
     fromDate, toDate]

employees is the to-many relationship from Department to Employee.

(See expressionForSubquery:usingIteratorVariable:predicate: in the "NSExpression Class Reference", where a similar problem and the SUBQUERY solution is documented).