How to Efficiently Update or Insert Rows in Entity Framework?

Update Row if it Exists, Else Insert Logic with Entity Framework

When working with Entity Framework, there are efficient ways to implement the logic for updating a row if it exists or inserting a new row.

Attached Objects

If dealing with an attached object (an object loaded from the current context instance), use the following approach:

if (context.ObjectStateManager.GetObjectStateEntry(myEntity).State == EntityState.Detached)
{
    context.MyEntities.AddObject(myEntity);
}

context.SaveChanges();

The object will automatically track changes, and the SaveChanges() call will perform the update or insert operation as needed.

Non-Attached Objects with Key Check

If the object's key value is available, you can use this code:

if (myEntity.Id != 0)
{
    context.MyEntities.Attach(myEntity);
    context.ObjectStateManager.ChangeObjectState(myEntity, EntityState.Modified);
}
else
{
    context.MyEntities.AddObject(myEntity);
}

context.SaveChanges();

This approach first checks if the object exists using its Id property. If it does, it attaches it to the context and marks it as modified. Otherwise, a new object is added.

Non-Attached Objects without Key Check

When the object's existence can't be determined by its key, use a lookup query:

var id = myEntity.Id;
if (context.MyEntities.Any(e => e.Id == id))
{
    context.MyEntities.Attach(myEntity);
    context.ObjectStateManager.ChangeObjectState(myEntity, EntityState.Modified);
}
else
{
    context.MyEntities.AddObject(myEntity);
}

context.SaveChanges();

This approach fetches the row matching the object's key from the database and performs the attachment or addition based on the result of the query.

The above is the detailed content of How to Efficiently Update or Insert Rows in Entity Framework?. For more information, please follow other related articles on the PHP Chinese website!