AMES/AMESCoreStudio.WebApi/Models/ESUNAMESContext.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.EntityFrameworkCore;
using AMESCoreStudio.WebApi;
using AMESCoreStudio.WebApi.Models.SYS;
using AMESCoreStudio.WebApi.Models.AMES;
using AMESCoreStudio.WebApi.Models.BAS;
using Microsoft.EntityFrameworkCore.Metadata;
using Microsoft.EntityFrameworkCore.Query.SqlExpressions;
using System.Reflection;


namespace AMESCoreStudio.WebApi
{
    /// <summary>
    /// 
    /// </summary>
    public class ESUNAMESContext : DbContext
    {
        /// <summary>
        /// 
        /// </summary>
        /// <param name="options"></param>
        public ESUNAMESContext(DbContextOptions<ESUNAMESContext> options)
            : base(options)
        {
            //Configuration.ProxyCreationEnabled = false;
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="datePartArg"></param>
        /// <param name="date"></param>
        /// <returns></returns>
        public int? DatePart(string datePartArg, DateTimeOffset? date) => throw new InvalidOperationException($"{nameof(DatePart)} cannot be called client side.");


        /// <summary>
        /// 
        /// </summary>
        /// <param name="modelBuilder"></param>
        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            var methodInfo = typeof(DbFunctionExtensions).GetMethod(nameof(DatePart));

            var datePartMethodInfo = typeof(ESUNAMESContext)
                .GetRuntimeMethod(nameof(ESUNAMESContext.DatePart), new[] { typeof(string), typeof(DateTimeOffset) });
            modelBuilder.HasDbFunction(datePartMethodInfo)
               .HasTranslation(args =>
                        new SqlFunctionExpression("DatePart",
                            new[]
                            {
                            new SqlFragmentExpression((args.ToArray()[0] as SqlConstantExpression).Value.ToString()),
                            args.ToArray()[1]
                            },
                            true,
                            new[] { false, false },
                            typeof(int?),
                            null
                        )
                    );

       
        }

    }
}