Should I call SaveChanges once or after each change?

Question

I need to make a few changes to my database in my controller.

foreach (var valueStream in model.ListValueStream)
{
    ValueStreamProduct vsp = new ValueStreamProduct(valueStream.Id, product.Id);
    db.ValueStreamProduct.Add(vsp);
}
db.SaveChanges();

Shoul I call SaveChanges at the end or every time I make changes?

Answer 1

It depends.

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Answer 2

db

Answer 3

1) .

public ActionResult Create() 
{ 
     db.ValueStreamProduct.Add(vsp);
     db.tbl.Add(tbl2);
     db.tbl.Add(tbl3);

     // only one time you can call savechanges()
     db.SaveChanges();
 }

2) ValueStreamProduct tbl2.

But you need to get your last inserted record id for the second table. code like this

 public ActionResult Create() 
 {
     db.ValueStreamProduct.Add(vsp); 
     db.SaveChanges();

     // getting last inserted record Id from ValueStreamProduct table.
     tbl2.Column = vsp.Id

     db.tbl.Add(tbl2);
     db.tbl.Add(tbl3);

     db.SaveChanges();
  }