对同一DBContext使用多个连接字符串

{
  "ConnectionStrings": {
    "MainDatabase": "Server=主数据库连接字符串",
    "ReadOnlyDatabase": "Server=只读数据库连接字符串"
  }
}

public class MyDbContextFactory
{
    private readonly IConfiguration _configuration;

    public MyDbContextFactory(IConfiguration configuration)
    {
        _configuration = configuration;
    }

    public MyDbContext CreateDbContext(bool useReadOnlyDatabase)
    {
        var connectionString = useReadOnlyDatabase
            ? _configuration.GetConnectionString("ReadOnlyDatabase")
            : _configuration.GetConnectionString("MainDatabase");

        var optionsBuilder = new DbContextOptionsBuilder<MyDbContext>();
        optionsBuilder.UseSqlServer(connectionString);

        return new MyDbContext(optionsBuilder.Options);
    }
}

public class MyService
{
    private readonly MyDbContextFactory _dbContextFactory;

    public MyService(MyDbContextFactory dbContextFactory)
    {
        _dbContextFactory = dbContextFactory;
    }

    public void DoSomething(bool useReadOnlyDatabase)
    {
        using (var dbContext = _dbContextFactory.CreateDbContext(useReadOnlyDatabase))
        {
            // 使用dbContext进行数据库操作
        }
    }
}