how to update child records when updating the Master table using Linq [closed]
- by user20358
I currently use a general repositry class that can update only a single table like so
public abstract class MyRepository<T> : IRepository<T>
where T : class
{
protected IObjectSet<T> _objectSet;
protected ObjectContext _context;
public MyRepository(ObjectContext Context)
{
_objectSet = Context.CreateObjectSet<T>();
_context = Context;
}
public IQueryable<T> GetAll()
{
return _objectSet.AsQueryable();
}
public IQueryable<T> Find(Expression<Func<T, bool>> filter)
{
return _objectSet.Where(filter);
}
public void Add(T entity)
{
_objectSet.AddObject(entity);
_context.ObjectStateManager.ChangeObjectState(entity, System.Data.EntityState.Added);
_context.SaveChanges();
}
public void Update(T entity)
{
_context.ObjectStateManager.ChangeObjectState(entity, System.Data.EntityState.Modified);
_context.SaveChanges();
}
public void Delete(T entity)
{
_objectSet.Attach(entity);
_context.ObjectStateManager.ChangeObjectState(entity, System.Data.EntityState.Deleted);
_objectSet.DeleteObject(entity);
_context.SaveChanges();
}
}
For every table class generated by my EDMX designer I create another class like this
public class CustomerRepo : MyRepository<Customer>
{
public CustomerRepo (ObjectContext context)
: base(context)
{
}
}
for any updates that I need to make to a particular table I do this:
Customer CustomerObj = new Customer();
CustomerObj.Prop1 = ...
CustomerObj.Prop2 = ...
CustomerObj.Prop3 = ...
CustomerRepo.Update(CustomerObj);
This works perfectly well when I am updating just to the specific table called Customer. Now if I need to also update each row of another table which is a child of Customer called Orders what changes do I need to make to the class MyRepository. Orders table will have multiple records for a Customer record and multiple fields too, say for example Field1, Field2, Field3.
So my questions are:
1.) If I only need to update Field1 of the Orders table for some rows based on a condition and Field2 for some other rows based on a different condition then what changes I need to do?
2.) If there is no such condition and all child rows need to be updated with the same value for all rows then what changes do I need to do?
Thanks for taking the time. Look forward to your inputs...
