Reading connection string in class library dotnet core

Question

Hi, I have a solution in which there are 2 projects 1. DotNet Core API 2.2 2. DotNet Core Class library There is a connection string defined in appsettings json file in api project. I want to read that connection string in class library project via dependency injection and return connection object. I have tried different approaches to resolve but nothing seems to be working for me. Can anyone explain or suggest a detailed example which can be reference point to implement the same. Thanks in advance. Thanks Dheeraj

Veerendra Annigere · Answer

In your class library project, you need to create a DB context class. Right-click and add new class in you're class library project and inherit BaseContext. Like below public class MyDBContext : BaseContext, IMyDBContext { public MyDBContext(IConfiguration configuration, IConnectionStringProvider connectionStringProvider) : base(configuration, connectionStringProvider, "ConnectionStringInAppSettingsKeyNameHere" ) { } } public interface IMyDBContext : IBaseContext { } Create DB Context factory like below public class DbContextFactory : IDesignTimeDbContextFactory { public MyDBContext CreateDbContext(string[] args) { IConfigurationRoot configuration = new ConfigurationBuilder() .SetBasePath(Directory.GetCurrentDirectory()) .AddJsonFile( "appsettings.json" ) .Build(); return new MyDBContext(configuration, null ); } } That's it. You can use this context to do all DB operations in you're class library project. Usage Example: public class MyAnOtherClass { private readonly IMyDBContext context; public MyAnOtherClass(IMyDBContext context) { this .context = context; } public PerformAnyDBOperstion(){ var con = context.DbContext.Database.GetDbConnection(); } } You need to add this in your main project, startup.cs services.AddScoped ();

Reading connection string in class library dotnet core

Answers (1)