As far as I can tell, changes made to the database by the following code to "MySite" are immediate:
public List<vcData> UpdateDisplayAndUrl(List<vcData> vcDataList)
{
foreach (vcData vcData in vcDataList)
{
_entities.ExecuteStoreCommand("UPDATE vcData SET DisplayItem = {0}, DisplayUrl = {1} WHERE ID = {2} ", vcData.DisplayItem, vcData.DisplayUrl, vcData.ID);
}
return GetTableData();
}
What I would like to do is to immediately return the newly updated records for further processing, essentially, re-query the changes that have just been made:
public List<vcData> GetTableData()
{
var result = (from td in _entities.vcData
where td.SiteID == "MySite"
select td).ToList();
return result;
}
In my controller code, I am trying to do something like:
_currentvcTickerDataList = Repository.UpdateDisplayAndUrl(vcUnupdatedDataList);
//.....do more stuff with _currentvcTickerDataList, which ought to contain updated information, should it not?
PROBLEM: the GetTableData() method does not seem to return the updated values, only the previous (unupdated) values.
I am new to LINQ, entity framework, and MVC, so I'm pretty certain there is something fundamental that I am missing.
You need to set the MergeOption to OverwriteChanges before querying. Please go through the MergeOptions explained in msdn to get a clear idea.
public List<vcData> GetTableData()
{
var currentMergeOption = _entities.vcData.MergeOption;
_entities.vcData.MergeOption = MergeOption.OverwriteChanges;
var result = (from td in _entities.vcData
where td.SiteID == "MySite"
select td).ToList();
//revert the change
_entities.vcData.MergeOption = currentMergeOption;
return result;
}
Related
Normally, with MVC I use db.savechanges() method after I do some processes. But check the below code when I use N-Tier Architecture in everyloop its gonna insert in this way but I dont want it. I have to check all the items first. If there is no problem then I have to insert it all together.
foreach (var item in mOrderList)
{
MOrder mOrder = new MOrder();
mOrder.StatusAdmin = false;
mOrder.Date = DateTime.Now;
mOrder.StatusMVendor = "Sipariş alındı.";
mOrder.HowMany = item.HowMany;
mOrder.MBasketId = item.MBasketId;
mOrder.MProductId = item.MProductId;
mOrder.MVendorId = item.MVendorId;
mOrder.WInvestorId = item.WInvestorId;
MProduct mprostock = _imProductService.GetMProductById(item.MProductId);
if (mprostock.Stock<=0)
{
return ReturnErrorAndSuccess(HttpStatusCode.NotFound, "MProduct", mprostock.Name + " ürününde stok kalmadığı için işlem tamamlanamadı.");
}
_imOrderService.InsertMOrder(mOrder);
}
all you have to do is:
first you should define a method that get list of mProductId and then return list of MProduct.
after that you should check if there is any record with Stock<=0 then return your error.
-also for your insert you should define a method that get list of MOrder and return appropriate datatype for example Boolean.
public List<MProduct> GetMProductByIds(List<MProductId> mProductId)
{
//getting record code
}
public bool AddMOrder(List<MOrder> mOrder)
{
//inserting record code
}
I have this Service that works to delete one (1) row from the database (Sorry for any lingo errors.):
public bool DeleteSchedulesFromDate(DateTime objDateTime)
{
var result = _db.Schedules.FirstOrDefault(x => x.AppointmentDateEnd <= objDateTime);
if (result != null)
{
_db.Schedules.Remove(result);
_db.SaveChanges();
}
else
{
return false;
}
return true;
}
This as the calling function:
private void DeleteSchedules(string dtEnd)
{
deleteScheduleDate = dtEnd;
DateTime _dtEnd;
if (DateTime.TryParse(dtEnd, out _dtEnd))
{
var result = #Service.DeleteSchedulesFromDate(_dtEnd);
schedules.Clear();
schedules = Service.GetSchedules();
if (result)
{
this.ShouldRender();
}
}
}
But how do I change it to delete all rows that matches the passed DateTime object?
I have tried :
to change it to a List, but then the bool doesn't work.
set a loop in the Service, but can't make it run correctly.
set a loop in the function call, but can't make it work either.
to google and look up other posts on SO, but found no match.
Instead of searching for the first match with FirstOrDefault you should get all valid result into a List (Where + ToList) and delete all of them (RemoveRange)
var result = _db.Schedules.Where(x => x.AppointmentDateEnd <= objDateTime).ToList();
if (result.Any())
{
_db.Schedules.RemoveRange(result);
_db.SaveChanges();
}
How I can do just this ( a.myFavorits.Add()) without pulling the all object to var a , because a has a lot of data, and I don't want to pull all a object, but I can't find a way do do it.
I want to do the lambada and the linq without return something but linq is always return something
public static void addFavorits(long f,long idUser)
{
using (var db = dataBase())
{
// here i pull object user from users table
var a = db.users.Where(c => c.id == idUser).SingleOrDefault();
// here i adding to the object field myFavorits new value
//myFavorits is also a table of entitys that connected to user object
a.myFavorits.Add(new BE.FavoritsUsersLong { myLong = f });
db.SaveChanges();
}
}
I thought to do something like this but i dont know how to set the field users_TableId that is the key that connect the 2 tables
public static void addFavorits(long favoritId,long idUser)
{
using (var db = dataBase())
{
db.favoritsUsersLong.Add(new BE.FavoritsUsersLong {myLong = favoritId}
/*,users_TableId =idUser*/);
db.SaveChanges();
}
}
Here's a concrete example that does what you want. In this example, only the Name of a Company is modified and saved. Or an item is added to one of its collections.
var cmp = new Company{ CmpId = 1, Name = "Cmp1" }; // CmpId is the primary key
db.Companies.Attach(cmp);
db.Entry(cmp).Property(c => c.Name).IsModified = true;
// Or add an entity to a collection:
cmp.Users = new[] {new User { Name = "a1", PassWord = "a1" } };
try
{
db.Configuration.ValidateOnSaveEnabled = false;
db.SaveChanges();
}
finally
{
db.Configuration.ValidateOnSaveEnabled = true;
}
Result in SQL:
DECLARE #0 VarChar(30) = 'Cmp1'
DECLARE #1 Int = 1
UPDATE [dbo].[Company]
SET [Name] = #0
WHERE ([CmpId] = #1)
There are a few things to note here:
Obviously you need to know the Id of the entity you want to modify.
The object you create is called a stub entity, which is an incomplete entity. When you try to save such an entity, EF is very likely to complain about null values in required properties. That's why almost certain you'd have to disable validation (temporarily, or, better, dispose the context immediately).
If you want to add an item to a collection, you should leave validation enabled, because you'd want to know for sure that the new entity is valid. So you shouldn't mix these two ways to use a stub entity.
If you often need roughly the same small part of your entity you may consider table splitting.
I'm guessing this is what you want? I don't see you 'editting' I only see you adding.
using (var db = dataBase())
{
var a = new user();
....
//set properties etc..
...
a.myFavorits.Add(new BE.FavoritsUsersLong { myLong = f });
db.users.Add(a);
db.SaveChanges();
}
The following code results in deletions instead of updates.
My question is: is this a bug in the way I'm coding against Entity Framework or should I suspect something else?
Update: I got this working, but I'm leaving the question now with both the original and the working versions in hopes that I can learn something I didn't understand about EF.
In this, the original non working code, when the database is fresh, all the additions of SearchDailySummary object succeed, but on the second time through, when my code was supposedly going to perform the update, the net result is a once again empty table in the database, i.e. this logic manages to be the equiv. of removing each entity.
//Logger.Info("Upserting SearchDailySummaries..");
using (var db = new ClientPortalContext())
{
foreach (var item in items)
{
var campaignName = item["campaign"];
var pk1 = db.SearchCampaigns.Single(c => c.SearchCampaignName == campaignName).SearchCampaignId;
var pk2 = DateTime.Parse(item["day"].Replace('-', '/'));
var source = new SearchDailySummary
{
SearchCampaignId = pk1,
Date = pk2,
Revenue = decimal.Parse(item["totalConvValue"]),
Cost = decimal.Parse(item["cost"]),
Orders = int.Parse(item["conv1PerClick"]),
Clicks = int.Parse(item["clicks"]),
Impressions = int.Parse(item["impressions"]),
CurrencyId = item["currency"] == "USD" ? 1 : -1 // NOTE: non USD (if exists) -1 for now
};
var target = db.Set<SearchDailySummary>().Find(pk1, pk2) ?? new SearchDailySummary();
if (db.Entry(target).State == EntityState.Detached)
{
db.SearchDailySummaries.Add(target);
addedCount++;
}
else
{
// TODO?: compare source and target and change the entity state to unchanged if no diff
updatedCount++;
}
AutoMapper.Mapper.Map(source, target);
itemCount++;
}
Logger.Info("Saving {0} SearchDailySummaries ({1} updates, {2} additions)", itemCount, updatedCount, addedCount);
db.SaveChanges();
}
Here is the working version (although I'm not 100% it's optimized, it's working reliably and performing fine as long as I batch it out in groups of 500 or less items in a shot - after that it slows down exponentially but I think that just may be a different question/subject)...
//Logger.Info("Upserting SearchDailySummaries..");
using (var db = new ClientPortalContext())
{
foreach (var item in items)
{
var campaignName = item["campaign"];
var pk1 = db.SearchCampaigns.Single(c => c.SearchCampaignName == campaignName).SearchCampaignId;
var pk2 = DateTime.Parse(item["day"].Replace('-', '/'));
var source = new SearchDailySummary
{
SearchCampaignId = pk1,
Date = pk2,
Revenue = decimal.Parse(item["totalConvValue"]),
Cost = decimal.Parse(item["cost"]),
Orders = int.Parse(item["conv1PerClick"]),
Clicks = int.Parse(item["clicks"]),
Impressions = int.Parse(item["impressions"]),
CurrencyId = item["currency"] == "USD" ? 1 : -1 // NOTE: non USD (if exists) -1 for now
};
var target = db.Set<SearchDailySummary>().Find(pk1, pk2);
if (target == null)
{
db.SearchDailySummaries.Add(source);
addedCount++;
}
else
{
AutoMapper.Mapper.Map(source, target);
db.Entry(target).State = EntityState.Modified;
updatedCount++;
}
itemCount++;
}
Logger.Info("Saving {0} SearchDailySummaries ({1} updates, {2} additions)", itemCount, updatedCount, addedCount);
db.SaveChanges();
}
The thing that keeps popping up in my mind is that maybe the Entry(entity) or Find(pk) method has some side effects? I should probably be consulting the documentation but any advice is appreciated..
It's a slight assumption on my part (without looking into your models/entities), but have a look at what's going on within this block (see if the objects being attached here are related to the deletions):
if (db.Entry(target).State == EntityState.Detached)
{
db.SearchDailySummaries.Add(target);
addedCount++;
}
Your detached object won't be able to use its navigation properties to locate its related objects; you'll be re-attaching an object in a potentially conflicting state (without the correct relationships).
You haven't mentioned what is being deleted above, so I may be way off. Just off out, so this is a little rushed, hope there's something useful in there.
This section simply reads from an excel spreadsheet. This part works fine with no performance issues.
IEnumerable<ImportViewModel> so=data.Select(row=>new ImportViewModel{
PersonId=(row.Field<string>("person_id")),
ValidationResult = ""
}).ToList();
Before I pass to a View I want to set ValidationResult so I have this piece of code. If I comment this out the model is passed to the view quickly. When I use the foreach it will take over a minute. If I hardcode a value for item.PersonId then it runs quickly. I know I'm doing something wrong, just not sure where to start and what the best practice is that I should be following.
foreach (var item in so)
{
if (db.Entity.Any(w => w.ID == item.PersonId))
{
item.ValidationResult = "Successful";
}
else
{
item.ValidationResult = "Error: ";
}
}
return View(so.ToList());
You are now performing a database call per item in your list. This is really hard on your database and thus your performance. Try to itterate trough your excel result, gather all users and select them in one query. Make a list from this query result (else the query call is performed every time you access the list). Then perform a match between the result list and your excel.
You need to do something like this :
var ids = so.Select(i=>i.PersonId).Distinct().ToList();
// Hitting Database just for this time to get all Users Ids
var usersIds = db.Entity.Where(u=>ids.Contains(u.ID)).Select(u=>u.ID).ToList();
foreach (var item in so)
{
if (usersIds.Contains(item.PersonId))
{
item.ValidationResult = "Successful";
}
else
{
item.ValidationResult = "Error: ";
}
}
return View(so.ToList());