How do I pass connection string to DBContext in Entity Framework Core?

Question

Is it possible to configure/pass connection string to the DbContext in the constructor?

public partial class MyContext : DbContext
{
    public MyContext() { }
    public MyContext(DbContextOptions<MyContext> options) : base(options) { }
}

MyContext opt = new MyContext("con_str");

rather than hard coding it in:

protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
    optionsBuilder.UseSqlServer(
        @"Server=(localdb)\mssqllocaldb;Database=MyDB;Integrated Security=True");
}

How do I use:

DbContextOptions<MyContext> opts;

The following answer: Pass connection string to code-first DbContext does not work.

Does this answer your question? [.Net Core passing connection string to DBContext class](https://stackoverflow.com/questions/39090206/net-core-passing-connection-string-to-dbcontext-class) — Michael Freidgeim, Sep 26 '21 at 12:31

Asherguru · Accepted Answer · 2020-08-18T08:48:23.310

6

Startup.cs

services.AddDbContext<YourDbContext>(options =>
{
     options.UseSqlServer(Configuration.GetSection("YourConn").Value);
     options.UseQueryTrackingBehavior(QueryTrackingBehavior.NoTracking);
});

appsettings.json

"YourConn": "yourconnectionstring"

EDITED

YourDbContext.cs

public partial class MyContext : DbContext
{
    private string _conn = "";
    public MyContext(string conn) 
    { 
        _conn = conn;
    }
    public MyContext(DbContextOptions<MyContext> options) : base(options) { }
    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
         optionsBuilder.UseSqlServer(_conn);
    }
}

Then you can use

MyContext opt = new MyContext("con_str");

edited Aug 18 '20 at 08:48

answered Aug 18 '20 at 08:38

Asherguru

1,687
1
5
10

What is startup.cs and appsettings.json. I don't use ASP.net core. I have remowed DI tag. What is services object? – mwal Aug 18 '20 at 08:41
what you use? winform? – Asherguru Aug 18 '20 at 08:43
Currently console application. – mwal Aug 18 '20 at 08:45
i edited post. you can check. Ignore startup.cs and appsettings.json. – Asherguru Aug 18 '20 at 08:48
1

Thx. That's what I needed. – mwal Aug 18 '20 at 08:57
Thank you @Asherguru, anyway I really had to implement this on bad condition that I really hate at... *look into my code, and cry... – Benyamin Limanto Sep 08 '22 at 07:50
DbContextOptions doesnt exist for me? – ThexBasic Sep 12 '22 at 15:10

How do I pass connection string to DBContext in Entity Framework Core?

1 Answers1

Startup.cs

appsettings.json

EDITED

YourDbContext.cs