I'm trying to implement the ASP .NET Core Identity with PostgreSQL. I'm also trying to migrate the database programmatically. The code I'm trying to use, looks like this:
using var scope = _serviceProvider.CreateScope();
var context = scope.ServiceProvider.GetRequiredService<ApplicationDbContext>();
await context.Database.MigrateAsync();
This will be called at the start up at Program.cs. I'm facing this issue where the ASP Identity tables were created but the exception Npgsql.PostgresException: '42P07: relation "AspNetRoles" already exists' was also thrown. What did I do wrong?
The reason for you are getting the exception is because the table AspNetRoles already exists in the database.
You can use the following code to check if there are any pending migrations and if there are any then execute the MigrateAsync() method:
var pendingMigrations = await context.Database.GetPendingMigrationsAsync();
if (pendingMigrations.Any())
{
await context.Database.MigrateAsync();
}
Read more about applying migrations automatically here: https://makolyte.com/ef-core-apply-migrations-programmatically/
Update based on comments
A good resource for getting started with migrations: https://www.learnentityframeworkcore.com/migrations
Related
I am attempting to execute an initial database creation migration using entity framework core against a postgres database.
The problem I am having is that I wish to create the tables under a custom schema.
I have managed to create an initial migration with no problems but when I attempt to "update-database" the migration fails with the following error.
Npgsql.PostgresException (0x80004005): 3F000: no schema has been selected to create in
at Npgsql.NpgsqlConnector.<>c__DisplayClass160_0.<g__ReadMessageLong|0>d.MoveNext()
Having initial looked into the issue I assumed this was simply because the schema was not being set in the context.
To get around this I set added the following code to the DbContext
protected override void OnModelCreating(ModelBuilder builder)
{
//Set the default schema
builder.HasDefaultSchema("ConfigStore");
//Continue with the call./Migrate
base.OnModelCreating(builder);
}
I still get the same error when running update-database.
I checked the initial migration Up() method and can clearly see the following code:
migrationBuilder.EnsureSchema(name: "ConfigStore");
The migration creates the database but nothing else so I assume the problem here is that the schema is not being created after the database which is then subsequently causing the table creations to fail.
The question I have is how do I fix this?
Can I execute some custom sql AFTER the database has been created but before the tables? Is there something I can do to get EnsureSchema() to create the schema first?
Thanks in advance
Would you believe it. Hours and hours trying to figure it out and 10 minutes after posting on stack overflow I find the solution....
The problem was the initial connection string. I had defined the connection string as follows:
Server=127.0.0.1; port=5432; user id=XXXX; password=XXXX; database=Test; pooling=true; SearchPath=ConfigStore
The problem was the search path. Apparently EF Migrations creates the database perfectly with this connection string but then attempts to access the tables before creating the schema causing the error reported. Removing the search_path from the connection string resulted in the schema being created first, then the tables. Odd - but hey it works.
I have my custom schema kernel. The following search path helped me to resolve the issue
"Host=localhost;Database=test08;SearchPath=kernel,public;Username=postgres;Password=strongPa$$123;"
I'm looping over a bunch of tables and have to delete records in each of them having a specific column name. I was able to get that list but the following line gives me the exception: Microsoft.Data.SqlClient.SqlException (0x80131904): Must declare the table variable "#p0".
foreach (var dsw in deleteSwModels)
{
contextCtx.Database.ExecuteSqlInterpolated($"DELETE FROM {dsw.Name} WHERE DeleteSw = 1");
}
The property Name looks like Person.Address where Person is the schema name under which the table is placed.
The version of Entity Framework Core is 3.1.8
I went digging further into the exception details and in the source code at Github ef core.
I solved the problem by making use of the following statement instead:
contextCtx.Database.ExecuteSqlRaw($"DELETE FROM {dsw.Name} WHERE DeleteSw = 1");
I hope it helps someone else in the future.
I've created migration for adding a field to the Postgres table, it works as expected on the existing database. But when I want to run the same vapor server with a new database it crashes on the migration with the "field already exists" message, which is, of course, understandable. But how to maintain the server code so it could work both with existing and new databases?
Fatal error: Error raised at top level: PostgreSQL Error: column "the_coloumn" of relation "User" already exists
- id: PostgreSQLError.server.error.check_for_column_name_collision
: file /BuildRoot/Library/Caches/com.apple.xbs/Sources/swiftlang/swiftlang-1100.8.280/swift/stdlib/public/core/ErrorType.swift, line 200
Assuming you have deployed the application and have multiple installations then you will need to preserve the two versions of the table. If you haven't then you could always delete the second migration if it does nothing more than add the field. As you have discovered, the field gets created in the first migration on a new installation.
However, if you have to have both then you will need to replace your use of AddProperties in the original migration that builds the table with an explicit list of the fields, less the one you are adding in the second migration. Examples of individual field creations are:
extension User:Migration
{
static func prepare(on connection:MySQLConnection) -> Future<Void>
{
return Database.create(self, on:connection)
{
builder in
builder.field(for:\.id, isIdentifier:true)
builder.field(for:\.surname, type:.varchar(30, characterSet:nil, collate:nil))
builder.field(for:\.firstName, type:.varchar(30, characterSet:nil, collate:nil))
}
}
}
This will build the table as you had it before when you created the table in the original database. Then your second migration will work as before. See https://docs.vapor.codes/3.0/fluent/migrations/ for more information.
Like several others I have tried to implement ASP.NET Identity Model First. Everything works fine once you have tried, errored, fumed, searched and resolved.. I thought.
See also:
ASP.NET Identity with EF Database First MVC5
http://danieleagle.com/blog/2014/05/setting-up-asp-net-identity-framework-2-0-with-database-first-vs2013-update-2-spa-template/
Course of action, summarized:
Created default project (MVC5)
Create database
Update connectionstring in the web.config
Run website, register: tables get created
Create EF Model (edmx)
Import Identity tables (everything fine up to this point)
Modified xxx.Context.tt to inherit from IdentityDbContext
Generate database script (trouble starts here)
I have solved the issues that appeared (up to the latest step). For completeness I will describe them.
Using the default Identity context
Everything works fine: tables get created, I can Register and login. This is however not the situation I want: I want to use a Model First approach.
Using the custom, model first context using the EF connectionstring
Modifying the CreatePerOwinContext so that it uses my Model First context:
public void ConfigureAuth(IAppBuilder app)
{
app.CreatePerOwinContext(CustomModelFirstDbContext.Create);
And the ApplicationUserManager so that it uses the Model First context:
public static ApplicationUserManager Create(IdentityFactoryOptions<ApplicationUserManager> options, IOwinContext context)
{
var manager = new ApplicationUserManager(new UserStore<ApplicationUser>(context.Get<CustomModelFirstDbContext>()));
Results in:
Server Error in '/' Application.
The entity type ApplicationUser is not part of the model for the
current context.
Description: An unhandled exception occurred during the execution of
the current web request. Please review the stack trace for more
information about the error and where it originated in the code.
Exception Details: System.InvalidOperationException: The entity type
ApplicationUser is not part of the model for the current context.
Source Error:
An unhandled exception was generated during the execution of the
current web request. Information regarding the origin and location of
the exception can be identified using the exception stack trace below.
Stack Trace:
[InvalidOperationException: The entity type ApplicationUser is not
part of the model for the current context.]
Using the "normal" connectionstring with the custom, Model First context
An exception of type
'System.Data.Entity.Infrastructure.UnintentionalCodeFirstException'
occurred in WebApplication1.dll but was not handled in user code
Additional information: Code generated using the T4 templates for
Database First and Model First development may not work correctly if
used in Code First mode. To continue using Database First or Model
First ensure that the Entity Framework connection string is specified
in the config file of executing application. To use these classes,
that were generated from Database First or Model First, with Code
First add any additional configuration using attributes or the
DbModelBuilder API and then remove the code that throws this
exception.
So, I figured I needed the default Identity context to use Identity, and use the custom Model First context for everything else. Not the preferred solution, but acceptable.
Rolled everything back
Import Identity tables from database
(Optional) Created entities via the Model First approach
Generated database script
Both the normal project and a quick sanity check test project have the same problem with the AspNetUserRoles table. That is a junction table, and when importing it in the EF designer, everything is OK. You won't see it since it is a many to many relationship, and when inspecting the association between AspNetRole and AspNetUser it looks good.
Designer and mapping details:
However, when generating the sql script, EF modifies the keys.
Designer and mapping details:
Generated SQL script:
-- Creating table 'AspNetUserRoles'
CREATE TABLE [dbo].[AspNetUserRoles] (
[AspNetRoles_Id] nvarchar(128) NOT NULL,
[AspNetUsers_Id] nvarchar(128) NOT NULL
);
GO
In EF, you can't change the names of the mappings in the designer (thread on social.msdn.microsoft.com).
Subsequently the creation of a new user wil fail, using the originally created context because the junction table contains the wrong columns:
Server Error in '/' Application.
Invalid column name 'UserId'.
Invalid column name 'UserId'.
Invalid column name 'UserId'.
Invalid column name 'RoleId'.
Invalid column name 'UserId'.
Description: An unhandled exception occurred during the execution of
the current web request. Please review the stack trace for more
information about the error and where it originated in the code.
Exception Details: System.Data.SqlClient.SqlException: Invalid column name 'UserId'. Invalid column name 'UserId'. Invalid column name 'UserId'. Invalid column name 'RoleId'. Invalid column name 'UserId'.
Source Error:
Line 89: {
Line 90: var user = new ApplicationUser() { UserName = model.Email, Email = model.Email };
Line 91: IdentityResult result = await UserManager.CreateAsync(user, model.Password);
Line 92: if (result.Succeeded)
Line 93: {
What is the solution? Are there any alternatives than trying to change the generated script, or moving to Code First?
If you in the begginning and db is still empty than
I believe the easiest workaround is:
Create EF Model(edmx).
Right click on model "Generate Database from model".
It will create DDL file (snippet below)
Replace all wrong "AspNetUsers_Id" and "AspNetRoles_Id" for correct values.
Right click "execute".
Works for me.
-- Creating non-clustered index for FOREIGN KEY 'FK_AspNetUserRoles_AspNetUser'
CREATE INDEX [IX_FK_AspNetUserRoles_AspNetUser]
ON [dbo].[AspNetUserRoles]
([AspNetUsers_Id]); //replace for UserId
Happy coding!
I created simple MVC application with a database.
First I created a database, initialized the database, then I created a model from the database and the application worked..
Then I decide to load database with totaly different values (but the definitons of tables/fields stayed the same)..
After reloading the database my application does not shows any data from my DB. Using debugger I saw that my application cannot get any data from the table.
Worse - I noticed that additional to my database TestDB, the database explorer is showing TestDB.mdf1 database, with the same definitions as testDB.mdf but table is empty...
Here is the code:
public ActionResult ShowQuestions()
{
TestDBEntities _db = new TestDBEntities(); // this is the database
ObjectSet<question> all_quest = _db.questions ; // this is the table
foreach (var x in all_quest)
{
..... // this part was never executed
}
return View(q_list);
}
Any ideas what I am doing wrong?
1- check the connection string in your MVC application (web.config). This will tell you which database is being used. Then go to this database and check if you have data in your tables.
If it's the wrong database, just amend the connection string.
2- If it's the correct database, but without data, just add data.
It may have been recreated by your ORM (who knows?).
3- What is the error you are getting? Or are you getting any error?