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Entity Framework: Cannot insert explicit value for identity column in table '[table]' when IDENTITY_INSERT is set to OFF
(1 answer)
Closed 8 months ago.
I made a few tables in EF and entered in some seed data where I give value to a few columns with a primary key. When I run the application I am getting the error message:
Cannot insert explicit value for identity column in table 'Persons' when IDENTITY_INSERT is set to OFF.
How do I turn it on? I read on here to use:
[DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
above the property that is a primary key. I am still getting the same error message unfortunately. Please help.
I added [DatabaseGenerated(DatabaseGeneratedOption.None)] to all my properties that have a primary key. When I ran the migration I can see that the identity column is removed, But I am still getting the same error message.
When I go into SQL SEO I can still see the identity column on my primary key. I tried refreshing the database. What am I doing wrong? The only thing I can do is go into properties and remove the identity, but why can't I do it the way mentioned above?
In EF Core 1.1.2, I got this to work with transactions. In my "database initializer" that put seed data into the tables. I used the technique from this EF6 answer. Here's a sample of the code:
using (var db = new AppDbContext())
using (var transaction = db.Database.BeginTransaction())
{
var user = new User {Id = 123, Name = "Joe"};
db.Users.Add(user);
db.Database.ExecuteSqlCommand("SET IDENTITY_INSERT MyDB.Users ON;");
db.SaveChanges();
db.Database.ExecuteSqlCommand("SET IDENTITY_INSERT MyDB.Users OFF");
transaction.Commit();
}
Had to deal with the same issue and this seems to be a clean solution.
Credit to >> https://github.com/dotnet/efcore/issues/11586
I have made some changes so it now works with .Net Core 3.1 + (Tested in .Net 5) and also added this Method SaveChangesWithIdentityInsert
public static class IdentityHelpers
{
public static Task EnableIdentityInsert<T>(this DbContext context) => SetIdentityInsert<T>(context, enable: true);
public static Task DisableIdentityInsert<T>(this DbContext context) => SetIdentityInsert<T>(context, enable: false);
private static Task SetIdentityInsert<T>(DbContext context, bool enable)
{
var entityType = context.Model.FindEntityType(typeof(T));
var value = enable ? "ON" : "OFF";
return context.Database.ExecuteSqlRawAsync(
$"SET IDENTITY_INSERT {entityType.GetSchema()}.{entityType.GetTableName()} {value}");
}
public static void SaveChangesWithIdentityInsert<T>(this DbContext context)
{
using var transaction = context.Database.BeginTransaction();
context.EnableIdentityInsert<T>();
context.SaveChanges();
context.DisableIdentityInsert<T>();
transaction.Commit();
}
}
Usage
var data = new MyType{SomeProp= DateTime.Now, Id = 1};
context.MyType.Add(data);
context.SaveChangesWithIdentityInsert<MyType>();
Improved solution based on NinjaCross' answer.
This code is added directly in the database context class and allows to save changes by also specifying that identity insert is needed for a certain type (mapped to a table).
Currently, I have only used this for integrative testing.
public async Task<int> SaveChangesWithIdentityInsertAsync<TEnt>(CancellationToken token = default)
{
await using var transaction = await Database.BeginTransactionAsync(token);
await SetIdentityInsertAsync<TEnt>(true, token);
int ret = await SaveChangesExAsync(token);
await SetIdentityInsertAsync<TEnt>(false, token);
await transaction.CommitAsync(token);
return ret;
}
private async Task SetIdentityInsertAsync<TEnt>(bool enable, CancellationToken token)
{
var entityType = Model.FindEntityType(typeof(TEnt));
var value = enable ? "ON" : "OFF";
string query = $"SET IDENTITY_INSERT {entityType.GetSchema()}.{entityType.GetTableName()} {value}";
await Database.ExecuteSqlRawAsync(query, token);
}
Steve Nyholm's answer works fine, but I will provide some extra explanation and some generic code with exception handling.
Normally the context takes care of the transaction, but in this case manually taking care of it is required. Why?
Database context will generate a BEGIN TRAN after the SET IDENTITY_INSERT is issued. This will make transaction's inserts to fail since IDENTITY_INSERT seems to affect tables at session/transaction level.
So, everything must be wrapped in a single transaction to work properly.
Here is some useful code to seed at key level (as opposed to table level):
Extensions.cs
[Pure]
public static bool Exists<T>(this DbSet<T> dbSet, params object[] keyValues) where T : class
{
return dbSet.Find(keyValues) != null;
}
public static void AddIfNotExists<T>(this DbSet<T> dbSet, T entity, params object[] keyValues) where T: class
{
if (!dbSet.Exists(keyValues))
dbSet.Add(entity);
}
DbInitializer.cs
(assumes that model class name is the same as table name)
private static void ExecuteWithIdentityInsertRemoval<TModel>(AspCoreTestContext context, Action<AspCoreTestContext> act) where TModel: class
{
using (var transaction = context.Database.BeginTransaction())
{
try
{
context.Database.ExecuteSqlCommand("SET IDENTITY_INSERT " + typeof(TModel).Name + " ON;");
context.SaveChanges();
act(context);
context.SaveChanges();
transaction.Commit();
}
catch(Exception)
{
transaction.Rollback();
throw;
}
finally
{
context.Database.ExecuteSqlCommand($"SET IDENTITY_INSERT " + typeof(TModel).Name + " OFF;");
context.SaveChanges();
}
}
}
public static void Seed(AspCoreTestContext context)
{
ExecuteWithIdentityInsertRemoval<TestModel>(context, ctx =>
{
ctx.TestModel.AddIfNotExists(new TestModel { TestModelId = 1, ModelCode = "Test model #1" }, 1);
ctx.TestModel.AddIfNotExists(new TestModel { TestModelId = 2, ModelCode = "Test model #2" }, 2);
});
}
The solution proposed by #sanm2009 contains some nice ideas.
However the implementation has some imperfections related to the misusage of Task/async/await.
The method SaveChangesWithIdentityInsert does not return Task, nor await for the calls to EnableIdentityInsert and DisableIdentityInsert.
This could lead to undesired side effects.
The following implementations supports both async/await, and non-awaitable paradigms.
#region IDENTITY_INSERT
public static void EnableIdentityInsert<T>(this DbContext context) => SetIdentityInsert<T>(context, true);
public static void DisableIdentityInsert<T>(this DbContext context) => SetIdentityInsert<T>(context, false);
private static void SetIdentityInsert<T>([NotNull] DbContext context, bool enable)
{
if (context == null) throw new ArgumentNullException(nameof(context));
var entityType = context.Model.FindEntityType(typeof(T));
var value = enable ? "ON" : "OFF";
context.Database.ExecuteSqlRaw($"SET IDENTITY_INSERT {entityType.GetSchema()}.{entityType.GetTableName()} {value}");
}
public static void SaveChangesWithIdentityInsert<T>([NotNull] this DbContext context)
{
if (context == null) throw new ArgumentNullException(nameof(context));
using var transaction = context.Database.BeginTransaction();
context.EnableIdentityInsert<T>();
context.SaveChanges();
context.DisableIdentityInsert<T>();
transaction.Commit();
}
#endregion
#region IDENTITY_INSERT ASYNC
public static async Task EnableIdentityInsertAsync<T>(this DbContext context) => await SetIdentityInsertAsync<T>(context, true);
public static async Task DisableIdentityInsertAsync<T>(this DbContext context) => await SetIdentityInsertAsync<T>(context, false);
private static async Task SetIdentityInsertAsync<T>([NotNull] DbContext context, bool enable)
{
if (context == null) throw new ArgumentNullException(nameof(context));
var entityType = context.Model.FindEntityType(typeof(T));
var value = enable ? "ON" : "OFF";
await context.Database.ExecuteSqlRawAsync($"SET IDENTITY_INSERT {entityType.GetSchema()}.{entityType.GetTableName()} {value}");
}
public static async Task SaveChangesWithIdentityInsertAsync<T>([NotNull] this DbContext context)
{
if (context == null) throw new ArgumentNullException(nameof(context));
await using var transaction = await context.Database.BeginTransactionAsync();
await context.EnableIdentityInsertAsync<T>();
await context.SaveChangesAsync();
await context.DisableIdentityInsertAsync<T>();
await transaction.CommitAsync();
}
#endregion
#Steve Nyholm answer is OK, But in .Net core 3 ExecuteSqlCommand is Obsolete, ExecuteSqlInterpolated replacement of ExecuteSqlCommand:
using (var db = new AppDbContext())
using (var transaction = db.Database.BeginTransaction())
{
var user = new User {Id = 123, Name = "Joe"};
db.Users.Add(user);
db.Database.ExecuteSqlInterpolated($"SET IDENTITY_INSERT MyDB.Users ON;");
db.SaveChanges();
db.Database.ExecuteSqlInterpolated($"SET IDENTITY_INSERT MyDB.Users OFF");
transaction.Commit();
}
Another way is to explicitly open a connection then SET IDENTITY_INSERT <table> ON.
var conn = context.Database.GetDbConnection();
if (conn.State != ConnectionState.Open)
conn.Open();
context.Database.ExecuteSqlCommand("SET IDENTITY_INSERT Posts ON");
var post = new WeblogPost()
{
Id= oldPost.Pk, // <!--- explicit value to Id field
Title = oldPost.Title,
...
};
context.Posts.Add(post);
conn.Close();
Apparently once a connection has been explicitly opened before an EF request, that connection is not automatically closed by EF, so the setting is applied to the same connection context.
This is the same reason that Steve's response with transactions works as transactions keep a connection alive.
Note: you don't want to put the connection into a using statement if you plan to use the same context again later in the application/request. The connection has to exist, so the best way to clear the connection context is to .Close() it, thereby returning EF to its default behavior of opening and closing the connection per operation.
Below solution worked for me.(Link)
I have added below annotations. and removed [Key] Annotation.
[KeyAttribute()]
[DatabaseGenerated(DatabaseGeneratedOption.None)]
public int Id { get; set; }
Namespace can be changed according to the entity framework version. For Entity framework core namespace is System.ComponentModel.DataAnnotations.Schema
I did not face a data migration since I have tried in a new project.
Another way is to use ExecuteSqlRaw. Unlike ExecuteSqlInterpolated, you do not have to convert your passed string to a formattable string type.
using (var db = new AppDbContext())
using (var transaction = db.Database.BeginTransaction())
{
var user = new User {Id = 123, Name = "Joe"};
db.Users.Add(user);
db.Database.ExecuteSqlRaw("SET IDENTITY_INSERT MyDB.Users ON");
db.SaveChanges();
db.Database.ExecuteSqlRaw("SET IDENTITY_INSERT MyDB.Users OFF");
transaction.Commit();
}
In order to add related entities with an object graph using the DbContext I used a DbCommandInterceptor which automatically sets INSERT_IDENTITY ON for the table in question and then OFF after the insert. This works with IDs manually set and DbContext.SaveChanges. I used it in my integration tests but after a performance optimization maybe it could be suitable for production code in some cases. Here is my answer to a similar SO question which explains the details.
Use "SET IDENTITY_INSERT [table] ON/OFF" into transaction
public static void TranslateDatabase(ref BDVContext bdvContext)
{
bdvContext.Foro.RemoveRange(bdvContext.Foro);
bdvContext.SaveChanges();
using (var transaction = bdvContext.Database.BeginTransaction())
{
bdvContext.Database.ExecuteSqlRaw("SET IDENTITY_INSERT [dbo].[Foro] On");
using (old_balsaContext db = new old_balsaContext())
{
long id = 0;
foreach (ForoA77 post in db.ForoA77.Where(x => x.Fecha > new DateTime(2000,1,1) & x.IdPadre == 0 ) )
{
bdvContext.Foro.Add(new Foro
{
Id = ++id
, ParentId = 0
, EditId = 0
, IdDomains = 2
, UserNick = post.IdUsuario == 1 ? bdvContext.Users.Where(x => x.Id == 2).Single().User : post.Nick?? ""
, IdUsers = post.IdUsuario == 1 ? (int?)2 : null
, Title = post.Asunto?? ""
, Text = post.Texto?? ""
, Closed = post.Cerrado?? false
, Banned = post.Veto?? false
, Remarqued = post.Remarcado?? false
, Deleted = false
, Date = post.Fecha?? new DateTime(2001,1,1)
});
}
}
bdvContext.SaveChanges();
bdvContext.Database.ExecuteSqlRaw("SET IDENTITY_INSERT [dbo].[Foro] Off");
transaction.Commit();
}
}
Note, my entityframework was generated by reverse engineering
If you don't want to use EF core's auto-generating primary key values feature, you can turn it off. You can add your data to the primary key It should resolve the error - Set Identity Insert off
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.None)]
public int StudentId { get; set; }
Setting Database Generation option to None helped me. You can find more about it here- https://learn.microsoft.com/en-us/ef/core/modeling/generated-properties?tabs=data-annotations
You should keep it off, dont turn it on !
Its turned off for good reasons (security performance)...
Do this instead in your code.
For example, outside your default Create controller when you need to _context.add() a new entry in your DB:
object mytable = new Mytable
{
//as in your model but without key field ! (its readonly)
myvar = "something",
myage = 50,
done = somefunctionToRetrieveData(somevar),
date = system.datetime.now(),
universalAnswer = 42
}
_context.Add(mytable);
await _context.SaveChangesAsync();
I have an angular 8 app with .net core web api 2.1 and MS SQL SERVER.
I have login and logout implementation for users.
After the user logins, he can add or delete programming langugages.
When I perform a delete operation, I get the error
database operation expected to affect 1 row(s) but actually effected
5 rows
But the code works properly for finding that particular user and the ID of the programming language that he wants to delete.
Here is the image from the table: https://imgur.com/a/taZtJ7d
As you can see there are no duplicates.
I think it is something about Concurrency Conflicts. That's why I added a try-catch block with DbUpdateConcurrencyException.
It works sometimes and sometimes not.
Here, you can find the definiton for the table https://imgur.com/a/YMCYkNy
When I try the following method to delete Users from MS SQL, it works as it should:
public async Task<IActionResult> DeleteProgrammingLanguage(string userId, int plId)
{
UserPL ps = new UserPL();
try
{
ps = await _context.PlUsers.Where(x => x.UserId == userId && x.ProgrammingLanguageId == plId).SingleAsync();
_context.PlUsers.Remove(ps);
await _context.SaveChangesAsync();
}
catch (DbUpdateConcurrencyException ex)
{
throw ex;
}
return Ok(ps);
}
I solved my problem with this solution.
public IActionResult DeleteProgrammingLanguage(string userId, int plId)
{
using (_context)
{
// Fetch a person from database and change phone number
var ps = _context.PlUsers.FirstOrDefault(x => x.UserId == userId && x.ProgrammingLanguageId == plId);
// Change the person's name in the database to simulate a concurrency conflict
_context.PlUsers.Remove(ps);
var saved = false;
while (!saved)
{
try
{
// Attempt to save changes to the database
_context.SaveChanges();
saved = true;
}
catch (DbUpdateConcurrencyException ex)
{
foreach (var entry in ex.Entries)
{
if (entry.Entity is UserPL)
{
var proposedValues = entry.CurrentValues;
var databaseValues = entry.GetDatabaseValues();
foreach (var property in proposedValues.Properties)
{
var proposedValue = proposedValues[property];
var databaseValue = databaseValues[property];
// TODO: decide which value should be written to database
// proposedValues[property] = <value to be saved>;
}
// Refresh original values to bypass next concurrency check
entry.OriginalValues.SetValues(databaseValues);
}
else
{
throw new NotSupportedException(
"Don't know how to handle concurrency conflicts for "
+ entry.Metadata.Name);
}
}
}
}
}
return NoContent();
}
I am working with chat server like Jobbr.net. when i close group chat tab then i am getting DbUpdateException was Unhandled by user code
Code:
public void CommitChanges()
{
_db.SaveChanges();
}
Click here to see screenshot
Looks like you got a problem with your data model or the data you want to persist. I guess some required field or foreign key is not set when you try to save the entity.
Try catching and logging the System.Data.Entity.Infrastructure.DbUpdateException. It should tell you which entity causes the problem. Here is some logging code that we use:
using NLog;
private static Logger Logger = LogManager.GetCurrentClassLogger();
try {
_db.SaveChanges();
}
catch (System.Data.Entity.Infrastructure.DbUpdateException upEx) {
if (upEx.Entries != null && upEx.Entries.Any()) {
Logger.Debug("DbUpdateException contained '{0}' entries:", upEx.Entries.Count());
// get info about the Entity that produced the error
foreach (var dbEntityEntry in upEx.Entries) {
if (dbEntityEntry.Entity != null) {
var entityType = dbEntityEntry.Entity.GetType();
try {
var id = entityType.GetProperty("Id").GetValue(dbEntityEntry.Entity, null);
Logger.Debug("DbUpdateException contains DbEntityEntry - Type: '{0}', Id: '{1}', State: '{2}'", entityType.Name, id, dbEntityEntry.State.ToString("G"));
} catch (Exception) {
Logger.Debug("DbUpdateException contains DbEntityEntry - Type '{0}', Id: unknown, State: '{2}'", entityType.Name, dbEntityEntry.State.ToString("G"));
}
}
}
}
}
I have the following Asp.Net MVC 4 scaffold code.
//
// POST: /Detail/Edit/5
[HttpPost]
public ActionResult Edit(Detail detail)
{
var dd = Details.FirstOrDefault(d => d.DetailId == detail.DetailId);
if (dd == null)
{
return HttpNotFound();
}
detail.UpdatedBy = User.Identity.Name;
detail.UpdateTime = DateTime.Now;
if (ModelState.IsValid)
{
_db.Entry(detail).State = EntityState.Modified;
_db.SaveChanges();
return RedirectToAction("Index", new { id = detail.MasterId });
}
return View(dealDetail);
}
However, the line _db.Entry(detail).State = EntityState.Modified; raise the following error. What's the correct way to update the detail line of a master/detail editing scenery?
An object with the same key already exists in the ObjectStateManager. The ObjectStateManager cannot track multiple objects with the same key.
This line:
var dd = Details.FirstOrDefault(d => d.DetailId == detail.DetailId);
will cause loading of Detail entity from the database. Now you have two Details with the same Id but only one (the one loaded by that query) can be used for persistence. You can change your code to:
if (!Details.Any(d => d.DetailId == detail.DetailId))
{
return HttpNotFound();
}
or update the attached detail (dd) for example by:
// All values of detail entity must be set in your HTTP post!
_db.Entry(dd).CurrentValues.SetValues(detail);
I'm having a hard time getting any of the inserts to work with SqlLite. I have a table created with the following schema:
create table drink_category ( _id integer not null primary key autoincrement, value unique);
When the attached code runs, I get a SQLiteCantOpenDatebaseException with the error message "cannot open database file (code 14)".
As you can see in the code, I access the table with a query without a problem. I also do a db.isOpen() to verify the database is OK. I have even added code after the block with the insert and everything works OK. Any help would be greatly appreciated.
public Boolean add(String strValue)
{
Boolean bStatus = true;
String strSql;
String sqlValue = strValue.replaceAll("'","\'\'");
if (bStatus)
{
if (strValue.isEmpty())
{
BarDB.getInstance().setErrorMessage("No value entered.");
bStatus = false;
}
}
if (bStatus)
{
strSql = "select value from " + "drink_category" + " where value = '" + sqlValue + "' ";
Cursor cursor = SqlDbAdapter.getInstance().getDatabase().rawQuery(strSql, null);
if (null == cursor)
{
BarDB.getInstance().setErrorMessage("Problem with the database.");
bStatus = false;
}
else if (cursor.getCount() > 0)
{
BarDB.getInstance().setErrorMessage("A Drink Category with that name already exists.");
bStatus = false;
}
}
if (bStatus)
{
ContentValues cvValues = new ContentValues();
cvValues.put("value", sqlValue);
SQLiteDatabase db = SqlDbAdapter.getInstance().getDatabase();
if (db.isOpen())
{
try
{
long lerror = db.insertOrThrow("drink_category", null, cvValues);
}
catch (SQLiteException sqle)
{
BarDB.getInstance().setErrorMessage(sqle.toString());
bStatus = false;
}
}
}
return bStatus;
}
FOUND IT: I am running this on an emulator and I was storing the database file in /data/data. I guess when you do an insert, sqlite needs to write to a journal file and that directory is read only. I moved the database to /data/data//databases and things are working OK now. A better error message would have been much more helpful!