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POCore Data one-to-many relation saving entity confusion
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  1. POCore Data one-to-many relation saving entity confusion
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    copied!<p>I am working on a project where I am using core data, but bit confused how to use it corectly.</p> <p>I have two entities students and college</p> <p>students has one-to-one relationship to college. That is every student will have one college. college has one-to-many relationship to student. that is college can have lot's of students.</p> <p>However, in my app I am letting the user to add the student first without any college info. So I am keeping the relationship to college optional. In a 2nd view, I let the user update the college information of a student.</p> <p>Now I am while adding a new student I am just updating the basic field related to student (firs name, last name, age, etc.). Now in 2nd view while updating college info I am not sure what is the correct way to do it considering the relationship.</p> <p>The first view pass the student object to 2nd view and I am updating it as follows:</p> <pre><code>College* college = (College*)[NSEntityDescription insertNewObjectForEntityForName:@"College" inManagedObjectContext:self.managedObjectContext]; college.name = @"name" college.address = @"address" [college addStudentObject:self.student]; </code></pre> <p>Am I doing it correctly? what should be the correct way:</p> <ol> <li><p>Adding the college object in 2nd view and connecting the entity by adding the student object in the student relation of a college?</p></li> <li><p>Retrieving the student object first then getting the empty college object from the college relation. Then updating the college object with data and then save the context.</p></li> </ol> <p>I am not sure if the 2nd option make any sense but in case of first option, if I add a new college, the new college get connected with the student but the old college remain in the database as redundant data. </p>
 

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