I'm saving a record in my database by passing 3 parameters, the number parameter is passed to pick the number of records from one table to another table. However the loop written inserts only 1 record instead of the number parameter passed.
I'm using the the Take() method in Entity Framework to pick the records. It inserts only the last records in the loop
public async Task<bool> Save(string company, int number, string registrationNumber)
{
using (var trans = _dbContext.Database.BeginTransaction())
{
var db = new SibaCiidDbContext();
var dbSet = _dbContext.Set<IntermediaryAssignment>();
// pick number of records
var data = await (from s in db.StickerDistributions
where s.Dispatched == false &&
s.CompanyCode == company
select s).Take(number).ToListAsync();
var intermediary = (await _repo.FindBy(s => s.RegistrationNumber == registrationNumber &&
s.Status == EntityStatus.Active)).FirstOrDefault();
var entity = new IntermediaryAssignment();
foreach (var sticker in data)
{
entity.CompanyCode = sticker.CompanyCode;
entity.StickerCode = sticker.StickerCode;
entity.RegistrationNumber = intermediary.RegistrationNumber;
entity.Status = EntityStatus.Active;
entity.CreatedDate = DateTime.Now;
entity.Dispatched = false;
entity.IntermediaryType = intermediary.IntermediaryType;
dbSet.Add(entity);
}
trans.Commit();
return await _dbContext.SaveChangesAsync() > 0;
}
}
You are creating one entity, and then updating it 3 times. You need to create a new entity for each new record.
Move the new IntermediaryAssignment() inside the loop.
foreach (var sticker in data)
{
var entity = new IntermediaryAssignment();
entity.CompanyCode = sticker.CompanyCode;
entity.StickerCode = sticker.StickerCode;
entity.RegistrationNumber = intermediary.RegistrationNumber;
entity.Status = EntityStatus.Active;
entity.CreatedDate = DateTime.Now;
entity.Dispatched = false;
entity.IntermediaryType = intermediary.IntermediaryType;
dbSet.Add(entity);
}
Related
IEnumerable<WebsiteWebPage> data = GetWebPages();
foreach (var value in data)
{
if (value.WebPage.Contains(".htm"))
{
WebsiteWebPage pagesinfo = new WebsiteWebPage();
pagesinfo.WebPage = value.WebPage;
pagesinfo.WebsiteId = websiteid;
db.WebsiteWebPages.Add(pagesinfo);
}
}
db.SaveChanges();
I want to add only distinct values to database in above code. Kindly help me how to do it as I am not able to find any solution.
IEnumerable<WebsiteWebPage> data = GetWebPages();
foreach (var value in data)
{
if (value.WebPage.Contains(".htm"))
{
var a = db.WebsiteWebPages.Where(i => i.WebPage == value.WebPage.ToString()).ToList();
if (a.Count == 0)
{
WebsiteWebPage pagesinfo = new WebsiteWebPage();
pagesinfo.WebPage = value.WebPage;
pagesinfo.WebsiteId = websiteid;
db.WebsiteWebPages.Add(pagesinfo);
db.SaveChanges();
}
}
}
This is the code that I used to add distinct data.I hope it helps
In addition to the code sample Furkan Öztürk supplied, Make sure your DB has a constraint so that you cannot enter duplicate values in the column. Belt and braces approach.
I assume that by "distinct values" you mean "distinct value.WebPage values":
// get existing values (if you ever need this)
var existingWebPages = db.WebsiteWebPages.Select(v => v.WebPage);
// get your pages
var webPages = GetWebPages().Where(v => v.WebPage.Contains(".htm"));
// get distinct WebPage values except existing ones
var distinctWebPages = webPages.Select(v => v.WebPage).Distinct().Except(existingWebPages);
// create WebsiteWebPage objects
var websiteWebPages = distinctWebPages.Select(v =>
new WebsiteWebPage { WebPage = v, WebsiteId = websiteid});
// save all at once
db.WebsiteWebPages.AddRange(websiteWebPages);
db.SaveChanges();
Assuming that you need them to be unique by WebPage and WebSiteId
IEnumerable<WebsiteWebPage> data = GetWebPages();
foreach (var value in data)
{
if (value.WebPage.Contains(".htm"))
{
WebsiteWebPage pagesinfo = new WebsiteWebPage();
if (db.WebsiteWebPages.All(c=>c.WebPage != value.WebPage|| c.WebsiteId != websiteid))
{
pagesinfo.WebPage = value.WebPage;
pagesinfo.WebsiteId = websiteid;
db.WebsiteWebPages.Add(pagesinfo);
}
}
}
db.SaveChanges();
UPDATE
To optimize this (given that your table contains much more data than your current list), override your equals in WebsiteWebPage class to define your uniqueness criteria then:
var myWebsiteWebPages = data.select(x=> new WebsiteWebPage { WebPage = x.WebPage, WebsiteId = websiteid}).Distinct();
var duplicates = db.WebsiteWebPages.Where(x=> myWebsiteWebPage.Contains(x));
db.WebsiteWebPages.AddRange(myWebsiteWebPages.Where(x=> !duplicates.Contains(x)));
this is a one database query to retrieve ONLY duplicates and then removing them from the list
You can use the following code,
IEnumerable<WebsiteWebPage> data = GetWebPages();
var templist = new List<WebsiteWebPage>();
foreach (var value in data)
{
if (value.WebPage.Contains(".htm"))
{
WebsiteWebPage pagesinfo = new WebsiteWebPage();
pagesinfo.WebPage = value.WebPage;
pagesinfo.WebsiteId = websiteid;
templist.Add(pagesinfo);
}
}
var distinctList = templist.GroupBy(x => x.WebsiteId).Select(group => group.First()).ToList();
db.WebsiteWebPages.AddRange(distinctList);
db.SaveChanges();
Or you can use MoreLINQ here to filter distinct the list by parameter like,
var res = tempList.Distinct(x=>x.WebsiteId).ToList();
db.WebsiteWebPages.AddRange(res);
db.SaveChanges();
This code saves my data to the database. The app records the time spent on each day of the month.
They write to the database in SQL Server, using EF. The problem is just that I would like them to overwrite instead of writing more
Controller:
List<Karta_Model> objNextKartaModel = new List<Karta_Model>();
for (int i = 0; i < liczbaDni; i++)
{
var modelNext = new Karta_Model()
{
Login = userName,
Rok = numerRoku,
Miesiac = numerMiesiaca,
DzMiesiaca = modelKarta.Model1[i].DzMiesiaca.Value,
DzTygodnia = modelKarta.Model1[i].DzTygodnia,
Rozpoczecie = modelKarta.Model1[i].Rozpoczecie
....
};
objNextKartaModel.Add(modelNext);
await _ecpContext.Karta.AddRangeAsync(objNextKartaModel);
await _ecpContext.SaveChangesAsync();
}
Id in SQL Server is defined as:
[Id] [int] IDENTITY(1,1)
I came up with the idea to extract the first row ID from the previously saved database
var nrIdBase = _ecpContext.Karta
.FirstOrDefault(f => f.DzMiesiaca == 1 &&
f.Miesiac == numerMiesiaca &&
f.Rok == numerRoku &&
f.Login == userName).Id;
but I don't know how to use it.
I tried something like this:
for (int i = 0; i < liczbaDni; i++)
{
var modelNext = new Karta_Model()
{
Id = nrIdBase +i,
Login = userName,
Rok = numerRoku,
Miesiac = numerMiesiaca,
DzMiesiaca = modelKarta.Model1[i].DzMiesiaca.Value,
DzTygodnia = modelKarta.Model1[i].DzTygodnia,
Rozpoczecie = modelKarta.Model1[i].Rozpoczecie
....
};
}
but I get an error:
InvalidOperationException: The instance of entity type 'Karta_Model' cannot be tracked because another instance with the same key value for {'Id'} is already being tracked. When attaching existing entities, ensure that only one entity instance with a given key value is attached. Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to see the conflicting key values.
Does anyone have an idea how to do this?
How to overwrite saved data once?
In order to update an existing recording in a database, you need to have it's ID before the update operation.
Then you can do this:
var existingRecord = _ecpContext.Karta.FirstOrDefault(x => x.Id == theExistingId);
if (existingRecord != null) {
existingRecord.Login = "CHANGED";
await _ecpContext.SaveChangesAsync()
}
This call that you are using:
await _ecpContext.Karta.AddRangeAsync(objNextKartaModel);
Is only for adding new items to the database.
Following the idea in my comment above, one thing you can do is to delete the existing data in the table before adding the new ones.
List<Karta_Model> objNextKartaModel = new List<Karta_Model>();
for (int i = 0; i < liczbaDni; i++)
{
var modelNext = new Karta_Model()
{
Login = userName,
Rok = numerRoku,
Miesiac = numerMiesiaca,
DzMiesiaca = modelKarta.Model1[i].DzMiesiaca.Value,
DzTygodnia = modelKarta.Model1[i].DzTygodnia,
Rozpoczecie = modelKarta.Model1[i].Rozpoczecie
....
};
objNextKartaModel.Add(modelNext);
//Add logic to delete the existing data
foreach(var model in _ecpContext.Karta)
{
_ecpContext.Karta.Remove(model);
}
await _ecpContext.Karta.AddRangeAsync(objNextKartaModel);
await _ecpContext.SaveChangesAsync();//One SaveChanges call is enough to update the database
}
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();
}
I pull student data from 2 databases. 1 from an online SOAP API which can handle async calls and 1 from a local DB with an older services that doesnt support async.
I compare these databases and write the differences in a local sqlDB through EF.
Problem:
I get double entries in my EF DB. He puts the correct data and amount in arrays inside the method, but it looks like once he hits the db.savechanges() he jumps back up a few line and saves again.
I don't even know where this extra thread comes from.
Some code might be still there from numerous tries to solve it. For instance I tried with addrange but I get an error when he tries to add the FullVarianceList.
public async Task<bool> FullStudentCompare(string date) //format DD/MM/YYYY
{
try
{
//DB context
using (var db = new SchoolDbContext())
{
//GET DATA
//SMT (async)
List<SmtStudent> smtStdudentList = await GetAllSmartschoolStudents();
//Wisa (sync)
//on date, or if emty on current systemdate
List<WisaStudent> wisaList;
if (date == "")
{
wisaList = GetWisaStudentData(DateTime.Now.ToShortDateString());
}
else
{
wisaList = GetWisaStudentData(date);
}
//Flags and props needed for DB entry after compare
bool existsInLocalDb = false;
List<Variance> vList = new List<Variance>();
//Full list to add to DB outside foreach
List<Variance> fullVarianceList = new List<Variance>();
//Full List of new Students to write to DB outside foreach
List<DbStudent> fullStudentList = new List<DbStudent>();
//Compare lists
foreach (WisaStudent wstd in wisaList)
{
//determine correct classCode
string klasCode;
if (wstd.klasgroep.Trim() == "Klasgroep 00")
{
klasCode = wstd.klas.Trim();
}
else
{
klasCode = wstd.klasgroep.Trim();
}
//Create SmtStudent object for compare
SmtStudent tempStd = new SmtStudent(true,
wstd.voornaam.Trim(),
wstd.naam.Trim(),
wstd.stamboeknummer.Trim(),
wstd.geslacht.Trim(),
wstd.geboortedatum.Trim(),
wstd.straat.Trim(),
wstd.huisnummer.Trim(),
wstd.busnummer.Trim(),
wstd.postcode.Trim(),
wstd.gemeente.Trim(),
wstd.emailadres.Trim(),
wstd.GSM_nummer.Trim(),
wstd.levensbeschouwing.Trim(),
wstd.coaccountmoedervoornaam.Trim(),
wstd.coaccountmoedernaam.Trim(),
wstd.coaccountmoederemailadres.Trim(),
wstd.coaccountmoederGSM_nummer.Trim(),
wstd.coaccountvadervoornaam.Trim(),
wstd.coaccountvadernaam.Trim(),
wstd.coaccountvaderemailadres.Trim(),
wstd.coaccountvaderGSM_nummer.Trim(),
klasCode,
wstd.nationaliteit,
wstd.geboorteGemeente,
wstd.geboorteLand
);
//Find matching SmtStudent
SmtStudent smtStd = smtStdudentList.Find(i => i.Internnummer == wstd.stamboeknummer);
//Find matching Std in local DB
DbStudent dbStd = await db.Students.Where(i => i.Stamboeknummer == wstd.stamboeknummer).FirstOrDefaultAsync();
//if none exists in the local DB create an entity to update and write to DB
if (dbStd == null)
{
dbStd = new DbStudent(wstd.voornaam.Trim(),
wstd.naam.Trim(),
wstd.stamboeknummer.Trim(),
wstd.geslacht.Trim(),
wstd.geboortedatum.Trim(),
wstd.straat.Trim(),
wstd.huisnummer.Trim(),
wstd.busnummer.Trim(),
wstd.postcode.Trim(),
wstd.gemeente.Trim(),
wstd.emailadres.Trim(),
wstd.GSM_nummer.Trim(),
wstd.levensbeschouwing.Trim(),
wstd.coaccountmoedervoornaam.Trim(),
wstd.coaccountmoedernaam.Trim(),
wstd.coaccountmoederemailadres.Trim(),
wstd.coaccountmoederGSM_nummer.Trim(),
wstd.coaccountvadervoornaam.Trim(),
wstd.coaccountvadernaam.Trim(),
wstd.coaccountvaderemailadres.Trim(),
wstd.coaccountvaderGSM_nummer.Trim(),
klasCode,
wstd.loopbaanDatum,
wstd.nationaliteit,
wstd.geboorteGemeente,
wstd.geboorteLand
);
db.Students.Add(dbStd);
fullStudentList.Add(dbStd);
}
else
{
existsInLocalDb = true;
}
if (smtStd == null)
{
//Std doesn't exist in Smt -> New student
dbStd.IsNewStudent = true;
dbStd.ClassMovement = true;
//remove from wisaList
wisaList.Remove(wstd);
}
else
{
//clear vlist from previous iterations
vList.Clear();
//get all properties on the obj, cycle through them and find differences
PropertyInfo[] props = smtStd.GetType().GetProperties();
vList.AddRange(props.Select(f => new Variance
{
Property = f.Name,
ValueA = f.GetValue(smtStd),
ValueB = f.GetValue(tempStd),
Checked = false
})
.Where(v => !v.ValueA.Equals(v.ValueB) && v.ValueB != null)
.ToList());
//If the users allrdy exists in LocalDb delete all previously recorded variances
if (existsInLocalDb)
{
if (db.Variances.Where(j => j.Student.StudentId.Equals(dbStd.StudentId)).FirstOrDefault() != null)
{ //if the student allready exists we will recreate the variancelist, hence deleting all current items first
List<Variance> existingList = db.Variances.Where(j => j.Student.StudentId.Equals(dbStd.StudentId)).ToList();
foreach (Variance v in existingList)
{
db.Variances.Remove(v);
}
}
}
//Add new variances if vList is not empty
if (vList.Count > 0)
{
//Check if KlasCode is a variance -> set classmovement to true
if (vList.Where(i => i.Property == "KlasCode").FirstOrDefault() != null)
{
dbStd.ClassMovement = true;
}
else
{
dbStd.ClassMovement = false;
}
//add the StudentObject to the variance to link them 1-many
foreach (Variance v in vList)
{
v.Student = dbStd;
fullVarianceList.Add(v);
db.Variances.Add(v);
}
}
}
}
//add the full lists of variances and new students to DB
//db.Variances.AddRange(fullVarianceList);
//db.Students.AddRange(fullStudentList);
db.SaveChanges();
return true;
}
}
catch(Exception ex)
{
return false;
}
}
A couple of things:
It is important to understand that EF uses a unit of work pattern where none of the changes to the entities are persisted until SaveChanges is called which explains the "once he hits the db.Savechanges() he jumps back up" phenomenon.
When you have a 1 to many relationsship and you assign a collection of entities to a navigation property on another entity and then add that parent entity to the DbContext, EF marks those child entities to be added too. In your case dbStd is added at the line "db.Students.Add(dbStd);" and at the line "v.Student = dbStd;". This is most likely what is causing your duplicates.
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.)