Using savechanges() inside foreach loop c#

Question

I have this method below that is writing data to two tables in the database. There is a collection I need to write to the database in the foreach section. why saveChanges does not work in each iteration of the loop and is there a better way of doing this? there is two things... first:the function does not return any thing .... second:the database did not up to date .... when i removed savechange() from the function it has works but with out changing values in database .

if (_context.ProductPins.Where(a => a.ProductId == id && a.Status==false).Count() > 0)
        {
            var c = 0;
            var ProductPins = _context.ProductPins.Where(a=>a.Status==false && a.ProductId == id);
            foreach(var item in ProductPins)
            {
                ApplicationUser.Balance = ApplicationUser.Balance - product.BuyingPrice;
                item.Equals(true);
                _context.Statements.Add(new Statement
                {
                    Amount = product.BuyingPrice,
                    RecordDate = DateTime.Now,
                    Destination = false,
                    FromApplicationUserId = _userManager.GetUserId(User),
                    //ToApplicationUserId = nu,
                    BalanceType = BalanceType.currentbalance,
                });

                _context.Update(ApplicationUser);
                _context.Update(item);
                _context.SaveChanges();
                c++;
                if (c > count)
                {
                    break;
                }





            }

Are you using Entity Framework? I know Dapper allows you to actually do collection based inserts, but that looks like Entity Framework is that correct? — Greg
– Greg, Commented Oct 8, 2019 at 22:10
OP, please specify what you mean by "does not work." Do you get an error? Exception? No error but data is not saved? Data is saved but not correctly? Or does it work to spec but you just don't like the code structure? — John Wu
– John Wu, Commented Oct 8, 2019 at 22:45
@JohnWu there is two things... first:the function does not return any thing .... second:the database did not up to date .... when i removed savechange() from the function it has works but with out changing values in database — mohammed alani
– mohammed alani, Commented Oct 8, 2019 at 23:19
@محمدالعاني - if you're running sql server as backend, could you check using sql profiler? SaveChanges() should return int showing number of records saved. (on side note, you can change _context.ProductPins.Where(a => a.ProductId == id && a.Status==false).Count() > 0 to _context.ProductPins.Any(a => a.ProductId == id && a.Status==false) and put _userManager.GetUserId(User) outside of the loop). — yob
– yob, Commented Oct 9, 2019 at 1:01

Slipoch · Accepted Answer · 2019-10-16 04:03:01Z

2

If you are saving to a database, you should queue these changes so that you can do one write at the end and process all of them at once rather than one at a time, this way you take advantage of the databases internal write processing.

answered Oct 16, 2019 at 4:03

Slipoch

78410 silver badges23 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

mohammed alani · Accepted Answer · 2019-10-11 19:09:15Z

I only put savechange() method out of froreach loop....savechanges() should be not inside loop

if (_context.ProductPins.Where(a => a.ProductId == id && a.Status==false).Count() > 0)
        {
            var c = 0;
            var ProductPins = _context.ProductPins.Where(a=>a.Status==false && a.ProductId == id);
            foreach(var item in ProductPins)
            {
                ApplicationUser.Balance = ApplicationUser.Balance - product.BuyingPrice;
                item.Equals(true);
                _context.Statements.Add(new Statement
                {
                    Amount = product.BuyingPrice,
                    RecordDate = DateTime.Now,
                    Destination = false,
                    FromApplicationUserId = _userManager.GetUserId(User),
                    //ToApplicationUserId = nu,
                    BalanceType = BalanceType.currentbalance,
                });

                _context.Update(ApplicationUser);
                _context.Update(item);

                c++;
                if (c > count)
                {
                    break;
                }





            }
_context.SaveChanges();

Collectives™ on Stack Overflow

Using savechanges() inside foreach loop c#

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related