Entity framework not saving new item - c#

I have odd problem. The code below wont save new LookupGroup objects
LookupGroup lookup = null;
using (var db = new WaybackDbContext())
{
lookup = db.LookupGroups.SingleOrDefault(x => x.Name.Equals(lookupName, StringComparison.InvariantCultureIgnoreCase));
if (lookup == null)
{
lookup = new LookupGroup
{
Name = lookupName
};
db.SaveChanges();
}
}
The LookupGroup is initiated but it isn't saved and its id is 0.
What could be stopping it from saving?

Add it to context:
if (lookup == null)
{
lookup = new LookupGroup
{
Name = lookupName
};
db.LookupGroups.Add(lookup);
db.SaveChanges();
}

Related

how to modify value of property has unique key in ef6

When i update value of specify product, i cannot update product.name because it has unique contain
builder.HasAlternateKey(x => x.Name);
when I call _context.SaveChange(); it cause this error message :"
The property 'Product.Name' is part of a key and so cannot be modified or marked as modified. To change the principal of an existing entity with an identifying foreign key, first delete the dependent and invoke 'SaveChanges', and then associate the dependent with the new principal"
how can I update productName field ? I leave my update code below:
try
{
var product = await _context.Products.FindAsync(request.Id);
if (product == null) throw new ProjectException($"Cannot find a product with id: {request.Id}");
product.Name = request.Name;
product.Price = request.Price;
product.Stock = request.Stock;
product.Description = request.Description;
product.productStatus = request.productStatus;
//Save image
if (request.ThumbnailImage != null)
{
var thumbnailImage = await _context.ProductImages.FirstOrDefaultAsync(i => i.IsDefault == true && i.ProductId == request.Id);
if (thumbnailImage != null)
{
thumbnailImage.FileSize = request.ThumbnailImage.Length;
thumbnailImage.ImagePath = await this.SaveFile(request.ThumbnailImage);
_context.ProductImages.Update(thumbnailImage);
}
else
{
product.ProductImages = new List<ProductImage>()
{
new ProductImage()
{
Caption = "Thumbnail image",
DateCreated = DateTime.Now,
FileSize = request.ThumbnailImage.Length,
ImagePath = await this.SaveFile(request.ThumbnailImage),
IsDefault = true,
SortOrder = 1
}
};
}
}
await _context.SaveChangesAsync();
return true;
}
catch (Exception e)
{
var xx = e.Message;//get message in debuging
var x = 1;//this line make me have time to read error message :(
return false;
}

Object multiple reference IEntityTracker error while saving audit table

first I know this question has been asked but I really couldn't find an answer nor find the root of the problem so maybe a someone points me in the right direction.
I'm having the An entity object cannot be referenced by multiple instances of IEntityChangeTracker. error when trying to save into the log tables.
for the log table, I'm using
https://github.com/thepirat000/Audit.NET/tree/master/src/Audit.EntityFramework
so inside my DbContext class where I define the dbset, I have to override the onscopecreated function
the problem here is that when context.Savechanges run for the first audit record for each table it works but after first record, I get the multiple reference error.
so let's say I have the following tables
Languages table. with the following values
English,French,German
Countries Table with the following values
UK,France,Germany
for languages table, if I change English to English3 and save it works It records to the audit table but then for languages table, I can not do any changes at any records it's the same in every table
what am I missing?
private void SaveToLogTable(AuditScope auditScope)
{
foreach (var entry in ((AuditEventEntityFramework)auditScope.Event).EntityFrameworkEvent.Entries)
{
if(entry.Action is null) return;
if (TABLES.Any(x => x.T_TABLE_NAME.Equals(entry.Table)))
{
var newLog = new LOGS
{
LOG_ACTION = ACTIONS.FirstOrDefault(x => x.A_DESC == entry.Action)?.A_CODE,
LOG_DATE = DateTime.Now,
USERS = MyGlobalSettings.MyUser
};
if (entry.Changes != null)
{
foreach (var changes in entry.Changes)
{
var ch = new CHANGES
{
CH_COLUMN = changes.ColumnName,
CH_NEW_VALUE = changes.NewValue.ToString(),
CH_ORIGINAL_VALUE = changes.OriginalValue.ToString()
};
newLog.CHANGES.Add(ch);
}
}
if (entry.ColumnValues != null)
{
foreach (var kv in entry.ColumnValues)
{
var val = new VALUES
{
ColumnName = kv.Key,
ColumnValue = kv.Value.ToString()
};
newLog.VALUES.Add(val);
}
}
TABLES.First(x => x.T_TABLE_NAME.Equals(entry.Table)).LOGS.Add(newLog);
}
else
{
var table = new TABLES {T_TABLE_NAME = entry.Table};
var newLog = new LOGS
{
LOG_ACTION = ACTIONS.FirstOrDefault(x => x.A_DESC.Equals(entry.Action))?.A_CODE,
LOG_DATE = DateTime.Now,
LOG_USER_REFNO = MyGlobalSettings.MyUser.U_ROWID
//USERS = MyGlobalSettings.MyUser
};
if (entry.Changes != null)
{
foreach (var changes in entry.Changes)
{
var ch = new CHANGES
{
CH_COLUMN = changes.ColumnName,
CH_NEW_VALUE = changes.NewValue.ToString(),
CH_ORIGINAL_VALUE = changes.OriginalValue.ToString()
};
newLog.CHANGES.Add(ch);
}
}
if (entry.ColumnValues != null)
{
foreach (var kv in entry.ColumnValues)
{
var val = new VALUES
{
ColumnName = kv.Key,
ColumnValue = kv.Value is null? "": kv.Value.ToString()
};
newLog.VALUES.Add(val);
}
}
table.LOGS.Add(newLog);
//TABLES.Attach(table);
//TABLES.First(x => x.T_TABLE_NAME.Equals(entry.Table)).LOGS.Add(newLog);
TABLES.Add(table);
//TablesList.Add(table);
}
//entry.Entity
}
}

C# Entity Framework Bulk Update

What is the best way to update multiple records in a list to speed up processing?
Currently, I'm updating about 15000 products, each with 3 different price sets and it takes the whole day to complete.
I need to update the prices all at once in code side, then commit those changes to the database in 1 go, instead of fetching each inventory item, updating its values, then attaching it to the context. Every single fetch is causing the delays.
Code
public void UpdatePricesFromInventoryList(IList<Domain.Tables.Inventory> invList)
{
var db = new UniStockContext();
foreach (var inventory in invList)
{
Domain.Tables.Inventory _inventory = db.Inventories
.Where(x => x.InventoryID == inventory.InventoryID)
.FirstOrDefault();
if (inventory.Cost.HasValue)
_inventory.Cost = inventory.Cost.Value;
else
_inventory.Cost = 0;
foreach (var inventoryPrices in inventory.AccInventoryPrices)
{
foreach (var _inventoryPrices in _inventory.AccInventoryPrices)
{
if (_inventoryPrices.AccInventoryPriceID == inventoryPrices.AccInventoryPriceID)
{
_inventoryPrices.ApplyDiscount = inventoryPrices.ApplyDiscount;
_inventoryPrices.ApplyMarkup = inventoryPrices.ApplyMarkup;
if (inventoryPrices.Price.HasValue)
_inventoryPrices.Price = inventoryPrices.Price.Value;
else
_inventoryPrices.Price = _inventory.Cost;
if (inventoryPrices.OldPrice.HasValue)
{
_inventoryPrices.OldPrice = inventoryPrices.OldPrice;
}
}
}
}
db.Inventories.Attach(_inventory);
db.Entry(_inventory).State = System.Data.Entity.EntityState.Modified;
}
db.SaveChanges();
db.Dispose();
}
I've also tried working my code according to this SOQ Entity Framework update/insert multiple entities
and it gave me and error. Here are the details:
Code:
public void UpdatePricesFromInventoryListBulk(IList<Domain.Tables.Inventory> invList)
{
var accounts = new List<Domain.Tables.Inventory>();
var db = new UniStockContext();
db.Configuration.AutoDetectChangesEnabled = false;
foreach (var inventory in invList)
{
accounts.Add(inventory);
if (accounts.Count % 1000 == 0)
{
db.Set<Domain.Tables.Inventory>().AddRange(accounts);
accounts = new List<Domain.Tables.Inventory>();
db.ChangeTracker.DetectChanges();
db.SaveChanges();
db.Dispose();
db = new UniStockContext();
}
}
db.Set<Domain.Tables.Inventory>().AddRange(accounts);
db.ChangeTracker.DetectChanges();
db.SaveChanges();
db.Dispose();
}
Error:
An entity object cannot be referenced by multiple instances of IEntityChangeTracker.
I would suggest changing the following:
Domain.Tables.Inventory _inventory = db.Inventories
.Where(x => x.InventoryID == inventory.InventoryID)
.FirstOrDefault();
To
Domain.Tables.Inventory _inventory = db.Inventories
.Single(x => x.InventoryID == inventory.InventoryID);
I'd still add the db.Configuration.AutoDetectChangesEnabled = false; after getting the context, and also use AsNoTracking:
Turn off EF change tracking for any instance of the context
that is because you are hit the database context at every loop to increase the performance you should get all the Inventories by one hit ,this is your problem try the below code and you will notice the performance :
public void UpdatePricesFromInventoryList(IList<Domain.Tables.Inventory> invList)
{
var db = new UniStockContext();
invIdsArray = invList.select(x => x.InventoryID).ToArray();
IList<Domain.Tables.Inventory> invListFromDbByOneHit = db.Inventories.Where(x => invIdsArray.Contains(x.InventoryID)).Tolist();
foreach (var inventory in invListFromDbByOneHit)
{
//Domain.Tables.Inventory _inventory = db.Inventories
//.Where(x => x.InventoryID == inventory.InventoryID)
//.FirstOrDefault();
if (inventory.Cost.HasValue)
_inventory.Cost = inventory.Cost.Value;
else
_inventory.Cost = 0;
foreach (var inventoryPrices in inventory.AccInventoryPrices)
{
foreach (var _inventoryPrices in _inventory.AccInventoryPrices)
{
if (_inventoryPrices.AccInventoryPriceID == inventoryPrices.AccInventoryPriceID)
{
_inventoryPrices.ApplyDiscount = inventoryPrices.ApplyDiscount;
_inventoryPrices.ApplyMarkup = inventoryPrices.ApplyMarkup;
if (inventoryPrices.Price.HasValue)
_inventoryPrices.Price = inventoryPrices.Price.Value;
else
_inventoryPrices.Price = _inventory.Cost;
if (inventoryPrices.OldPrice.HasValue)
{
_inventoryPrices.OldPrice = inventoryPrices.OldPrice;
}
}
}
}
db.Inventories.Attach(_inventory);
db.Entry(_inventory).State = System.Data.Entity.EntityState.Modified;
}
db.SaveChanges();
db.Dispose();
}

Enter new data in db (EF)

I have method in controller
It receive data from post request and write to table
Here is code
[ResponseType(typeof(TimeTable))]
public IHttpActionResult PostTimeTable(TimeTable timeTable)
{
if (!ModelState.IsValid)
{
return BadRequest(ModelState);
}
if (ModelState.IsValid)
{
DateTime dt = DateTime.Today;
TimeTable c = (from x in db.TimeTables
where x.Company == timeTable.Company && x.INN == timeTable.INN
select x).First();
c.StartPause = timeTable.StartPause;
c.StartDay = timeTable.StartDay;
c.EndPause = timeTable.EndPause;
c.EndDay = timeTable.EndDay;
db.SaveChanges();
}
db.TimeTables.Add(timeTable);
db.SaveChanges();
return CreatedAtRoute("DefaultApi", new { id = timeTable.Id }, timeTable);
}
But it works well when record with INN and Company already in db.
But if it not in database I need to create new entry.
How I need to modify this method?
You can use a flag (exisingCompanyFlag) for edit mode or add new mode like this
bool existingCompanyFlag = true;
TimeTable c = (from x in db.TimeTables
where x.Company == timeTable.Company && x.INN == timeTable.INN
select x).FirstOrDefult();
if (c == null)
{
existingCompanyFlag = false;
c = new TimeTable();
}
c.StartPause = timeTable.StartPause;
c.StartDay = timeTable.StartDay;
c.EndPause = timeTable.EndPause;
c.EndDay = timeTable.EndDay;
if (!existingCompanyFlag)
db.TimeTables.Add(c);
You need a separate branch in your code for the insert case.
if (ModelState.IsValid) {
if (addingNewRow) {
TimeTable tt = new TimeTable {
// Populate properties (except identity columns)
};
db.TimeTables.Add(tt);
} else {
// update
}
db.SaveChanges();
}
To link to other entities use one of:
Assign instances:
x.Company = theCompany;
or, assign the instance id
x.CompanyId = companyId;
(#1 is easier if you already have the other entity loaded or are creating it – EF will sort out the ids – while #2 saves loading the whole other entity.)

Insert data using Entity Framework model

I'm trying to insert some data in my database using Entity Framework model, but for some unknown reasons to me, it does nothing.
Am I missing something here?
using (var context = new DatabaseEntities())
{
var t = new test
{
ID = Guid.NewGuid(),
name = "blah",
};
context.AddTotest(t);
context.SaveChanges();
}
It should be:
context.TableName.Add(TableEntityInstance);
For versions of entity framework before 6, it was:
context.TableName.AddObject(TableEntityInstance);
Where:
TableName: the name of the table in the database.
TableEntityInstance: an instance of the table entity class.
If your table is Orders, then:
Order order = new Order();
context.Orders.Add(order);
For example:
var id = Guid.NewGuid();
// insert
using (var db = new EfContext("name=EfSample"))
{
var customers = db.Set<Customer>();
customers.Add( new Customer { CustomerId = id, Name = "John Doe" } );
db.SaveChanges();
}
Here is an example:
public void UpdatePlayerScreen(byte[] imageBytes, string installationKey)
{
var player = (from p in this.ObjectContext.Players where p.InstallationKey == installationKey select p).FirstOrDefault();
var current = (from d in this.ObjectContext.Screenshots where d.PlayerID == player.ID select d).FirstOrDefault();
if (current != null)
{
current.Screen = imageBytes;
current.Refreshed = DateTime.Now;
this.ObjectContext.SaveChanges();
}
else
{
Screenshot screenshot = new Screenshot();
screenshot.ID = Guid.NewGuid();
screenshot.Interval = 1000;
screenshot.IsTurnedOn = true;
screenshot.PlayerID = player.ID;
screenshot.Refreshed = DateTime.Now;
screenshot.Screen = imageBytes;
this.ObjectContext.Screenshots.Add(screenshot);
this.ObjectContext.SaveChanges();
}
}
var context = new DatabaseEntities();
var t = new test //Make sure you have a table called test in DB
{
ID = Guid.NewGuid(),
name = "blah",
};
context.test.Add(t);
context.SaveChanges();
Should do it
[HttpPost] // it use when you write logic on button click event
public ActionResult DemoInsert(EmployeeModel emp)
{
Employee emptbl = new Employee(); // make object of table
emptbl.EmpName = emp.EmpName;
emptbl.EmpAddress = emp.EmpAddress; // add if any field you want insert
dbc.Employees.Add(emptbl); // pass the table object
dbc.SaveChanges();
return View();
}

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