Using ASP.NET Core Web API WITHOUT Entity Framework

This is possible.

The first problem you will run into is getting the database connection string. You will want to import the configuration to do so. In a controller, it might look like this:

    private readonly IConfiguration _configuration;

    public WeatherForecastController(ILogger<WeatherForecastController> logger, IConfiguration configuration)
    {
        _logger = logger;
        _configuration = configuration;
    }

Add using System.Data and using System.Data.SqlClient (you'll need NuGet for SqlClient) as well as using Microsoft.Extensions.Configuration. With access to the database, you are writing code "old style", for example:

    [HttpGet]
    [Route("[controller]/movies")]
    public IEnumerable<Movie> GetMovies()
    {
        List<Movie> movies = new List<Movie>();

        string connString = ConfigurationExtensions.GetConnectionString(_configuration, "RazorPagesMovieContext");
        SqlConnection conn = new SqlConnection(connString);
        conn.Open();

        SqlDataAdapter sda = new SqlDataAdapter("SELECT * FROM Movie", conn);
        DataSet ds = new DataSet();
        sda.Fill(ds);
        DataTable dt = ds.Tables[0];
        sda.Dispose();

        foreach (DataRow dr in dt.Rows)
        {
            Movie m = new Movie
            {
                ID = (int)dr["ID"],
                Title = dr["Title"].ToString(),
                ReleaseDate = (DateTime)dr["ReleaseDate"],
                Genre = dr["Genre"].ToString(),
                Price = (decimal)dr["Price"],
                Rating = dr["Rating"].ToString()
            };
            movies.Add(m);
        }
        conn.Close();
        return movies.ToArray();
    }

The connection string name is in appsettings.json.

"ConnectionStrings": {
"RazorPagesMovieContext": "Server=localhost;Database=Movies;Trusted_Connection=True;MultipleActiveResultSets=true"
 }

Yes it is possible. Just implement the API by yourself. Or here is also sample for the identity scaffold, without EF.

https://markjohnson.io/articles/asp-net-core-identity-without-entity-framework/

Just used Dapper as our ORM in a project rather than EF.

https://dapper-tutorial.net/

It is similar to ADO.Net, but it has some additionally features that we leveraged and it was really clean to implement.

I realize this is an old question, but it came up in a search I ran so I figured I'd add to the answers given.

First, if the custom stored procedures are your concern, you can still run them using Entity Framework's .FromSql method (see here for reference: https://www.entityframeworktutorial.net/efcore/working-with-stored-procedure-in-ef-core.aspx) The relevant info is found at the top of the page:

EF Core provides the following methods to execute a stored procedure:
1. DbSet<TEntity>.FromSql(<sqlcommand>)
2. DbContext.Database.ExecuteSqlCommand(<sqlcommand>)

If you are avoiding Entity Framework for other reasons, it's definitely possible to use any database connection method you want in ASP.NET Core. Just implement your database connection methods using whatever library is relevant to your database and set up your controller to return the data in whatever format you want. Most, if not all, of Microsoft's examples return Entity Framework entities, but you can easily return any data format you want.

As an example, this controller method returns a MemoryStream object after running a query against an MS SQL server (note, in most cases where you want data returned it's my understanding that it should be a "GET" method, not "POST" as is done here, but I needed to send and use information in the HttpPost body)

[HttpPost]
[Route("Query")]
public ActionResult<Stream> Query([FromBody]SqlDto content)
{
    return Ok(_msSqlGenericService.Query(content.SqlCommand, content.SqlParameters));
}

Instead of a MemoryStream, you could return a generic DataTable or a List of any custom class you want. Note that you'll also need to determine how you are going to serialize/deserialize your data.