何时在 DbContext 构造函数与 OnConfiguring 中提供 DbContextOptions？

Question

What is the difference between providing a DbContext constructor that accepts DbContextOptions<MyFileContext> versus including OnConfiguring method that wires-up database?

Are the two are equivalent?

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations.Schema;

using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.SqlServer;

namespace MyApp.Models
{
    public class MyDbContext : DbContext
    {
        // OPTION 1
        public MyDbContext(DbContextOptions<MyFileContext> options) : base(options)
        {
        }

        public DbSet<MyTable> MyTables { get; set; }

        // OPTION 2
        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            base.OnConfiguring(optionsBuilder);

            optionsBuilder.UseSqlServer(AppSettingsProvider.MySqlServerConnection);
        }

    }
}

Answer 1

Are the two are equivalent?

It's complicated. (But ideally no);

The DbContextOptions can be supplied to the DbContext by overriding the OnConfiguring method or externally via a constructor argument.

If both are used, OnConfiguring is applied last and can overwrite options supplied to the constructor argument.

emphasis mine

Reference Configuring a DbContext