How to get DbContext in ABP service?

Question

How to get DbContext instance in application layer?

I tried:

1.

public class SeedingTestDataAppService : MyAppServiceBase
{
    private readonly MyDbContext _ctx;

    public SeedingTestDataAppService
    (
        MyDbContext context // Error
    )
    {
        _ctx = context;
    }
}

2.

public class SeedingTestDataAppService : MyAppServiceBase
{
    private readonly MyDbContext _ctx;

    public SeedingTestDataAppService
    (
        IDbContextProvider<MyDbContext> dbContextProvider
    )
    {
        _ctx = dbContextProvider.GetDbContext();
        // Error: unitOfWork is null
    }
}

I am not good at ABP. Where and how can I take a DbContext instance and inject it?

Answer 1

Do not call dbContextProvider.GetDbContext() in the constructor.

Implement _ctx as a getter and use it wherever you actually need the context.

public class SeedingTestDataAppService : MyAppServiceBase
{
    private MyDbContext _ctx => _dbContextProvider.GetDbContext();
    private readonly IDbContextProvider<MyDbContext> _dbContextProvider;

    public SeedingTestDataAppService(IDbContextProvider<MyDbContext> dbContextProvider)
    {
        _dbContextProvider = dbContextProvider;
    }
}