Microsoft.entityframeworkcore.database.connection[20004]

Query: microsoft.entityframeworkcore.database.connection[20004]

This query refers to the Microsoft.EntityFrameworkCore.Database.Connection error with the error code 20004.
It is an error related to the connection to the database in the Entity Framework Core (EF Core) library provided by Microsoft for.NET applications.

EF Core is an Object-Relational Mapping (ORM) tool that allows developers to interact with databases using .NET objects.
The Connection error with code 20004 indicates an issue related to the database connection in EF Core.

Possible Causes

• Invalid database connection string
• Database server connectivity issues
• Insufficient permissions to access the database
• Incompatible database provider or version

Solution

To resolve the Microsoft.EntityFrameworkCore.Database.Connection[20004] error, you can follow these steps:

1. Verify the database connection string: Make sure the connection string provided in your application’s configuration (e.g., appsettings.json) is accurate and properly formatted according to the database provider you are using (e.g., SQL Server, MySQL, PostgreSQL).
2. Check the database server’s availability: Ensure that the database server you are trying to connect to is running and accessible from your application’s environment. Verify if the server’s network connectivity has not been interrupted.
3. Check the database user’s permissions: Ensure that the user specified in the connection string has sufficient permissions to connect to the database and perform the required operations (e.g., read, write). Grant necessary permissions if required.
4. Ensure compatible EF Core and database provider versions: Verify if your EF Core library and the associated database provider are compatible and up-to-date. Consult the official documentation of EF Core and the database provider for any known compatibility issues.

Example

Here’s an example of a connection string used in an ASP.NET Core application’s appsettings.json file for connecting to a SQL Server database:

    
{
  "ConnectionStrings": {
    "DefaultConnection": "Server=(localdb)\\MSSQLLocalDB;Database=MyDatabase;Trusted_Connection=True;"
  }
}