Entity Framework Core on MySql calling FromSqlInterpolated and return list of entities

Question

I am using C# in an ASP Core project with Entity Framework Core 5.0.3, and using the Pomelo EntityFrameworkCore for MySql.

I am able to call standard SP's just fine with the below method:

int recordCount = await context.Database.ExecuteSqlInterpolatedAsync($"call `SP_ON_MYSQL` ({param1}, {param2}");

The SP in question outputs a result set of the Entity that I want to capture, and when I try this:

var qry = await context.ENITY.FromSqlInterpolated($"call `SP_ON_MYSQL` ({param1}, {param2})").SingleOrDefaultAsync();

I get the following error:

*'FromSqlRaw' or 'FromSqlInterpolated' was called with non-composable SQL and with a query composing over it.

Thank you in advance for any help that can be offered. Consider calling 'AsEnumerable' after the method to perform the composition on the client side.*

I have seen examples of this working with SQL Server, so please don't mark as already answered, unless you can show me an example that is not SQL Server specific.

Answer 1

Try this:

var qry = await context.ENITY
  .FromSqlInterpolated($"call `SP_ON_MYSQL` ({param1}, {param2})")
  .ToListAsync()
  .SingleOrDefault();

Answer 2

The answer of @Torvin is correct.

You need to add a AsEnumerable() , ToList() etc. call before the SingleOrDefault() call, if you are querying from a stored procedure. See Re-introduce detection for non-composable SQL in FromSql #17558 on the official EF Core repo for more information.

Here is a fully working console program, that demonstrates the approach:

using System.Diagnostics;
using System.Linq;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;
using Pomelo.EntityFrameworkCore.MySql.Infrastructure;

namespace IssueConsoleTemplate
{
    public sealed class IceCream
    {
        public int IceCreamId { get; set; }
        public string Name { get; set; }
    }
    
    public class Context : DbContext
    {
        public DbSet<IceCream> IceCreams { get; set; }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            optionsBuilder
                .UseMySql(
                    "server=127.0.0.1;port=3306;user=root;password=;database=So67040870",
                    b => b.ServerVersion("8.0.21-mysql")
                          .CharSetBehavior(CharSetBehavior.NeverAppend))
                .UseLoggerFactory(
                    LoggerFactory.Create(
                        b => b
                            .AddConsole()
                            .AddFilter(level => level >= LogLevel.Information)))
                .EnableSensitiveDataLogging()
                .EnableDetailedErrors();
        }
    }

    internal class Program
    {
        private static void Main()
        {
            using var context = new Context();

            SetupDatabase(context);

            var iceCreamId = 1;
            var searchContacts = context.IceCreams
                .FromSqlInterpolated($"CALL `GetIceCreams`({iceCreamId})")
                .AsEnumerable() // <-- Mandatory: Use AsEnumerable(), ToList() etc. or you will get an exception.
                .SingleOrDefault();

            Trace.Assert(searchContacts != null);
            Trace.Assert(searchContacts.Name == "Vanilla");
        }

        private static void SetupDatabase(Context context)
        {
            context.Database.EnsureDeleted();
            context.Database.EnsureCreated();

            var connection = context.Database.GetDbConnection();
            connection.Open();

            using var command = connection.CreateCommand();
            command.CommandText = @"CREATE PROCEDURE `GetIceCreams`(`someArg` int)
BEGIN
    SELECT someArg as `IceCreamId`, 'Vanilla' as `Name`;
END";
            command.ExecuteNonQuery();
        }
    }
}