Generic Repository

IRepository.cs

using System;
using System.Collections.Generic;

namespace Project.Repository
{
    public interface IRepository<TEntity> where TEntity : class
    {
        IEnumerable<TEntity> GetAll();

        IEnumerable<TEntity> GetAllByExpression(Func<TEntity, bool> expression);

        TEntity GetByExpression(Func<TEntity, bool> expression);

        TEntity GetById(int id);

        TEntity AddNew(TEntity model);

        TEntity Update(TEntity model);

        bool Delete(int id);

        void SaveDb();
    }
}

Repository.cs

using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;

namespace Project.Repository
{
    public class Repository<TEntity> : IRepository<TEntity> where TEntity : class
    {
        private readonly AppDbContext _appDb;

        public Repository(AppDbContext appDb)
        {
            try
            {
                appDb.ChangeTracker.QueryTrackingBehavior = QueryTrackingBehavior.NoTracking;
            }
            catch (Exception)
            {
            }
            _appDb = appDb;
        }

        private DbSet<TEntity> EntityTable => _appDb.Set<TEntity>();

        private string PrimaryKey => _appDb.Model.FindEntityType(typeof(TEntity)).FindPrimaryKey().Properties.Select(x => x.Name).FirstOrDefault();

        private Func<TEntity, bool> LinqExpression(object Pk)
        {
            var entity = Expression.Parameter(typeof(TEntity));
            Expression keyValue = Expression.Property(entity, PrimaryKey);
            Expression pkValue = Expression.Constant(Pk, keyValue.Type);
            Expression body = Expression.Equal(keyValue, pkValue);
            var lambda = Expression.Lambda<Func<TEntity, bool>>(body, entity);

            return lambda.Compile();
        }

        public IEnumerable<TEntity> GetAll()
        {
            var all = EntityTable.ToList();
            return all;
        }

        public IEnumerable<TEntity> GetAllByExpression(Func<TEntity, bool> expression)
        {
            var all = EntityTable.Where(expression).ToList();

            return all;
        }

        public TEntity GetByExpression(Func<TEntity, bool> expression)
        {
            TEntity entity = EntityTable.FirstOrDefault(expression);

            return entity;
        }

        public TEntity GetById(int id)
        {
            TEntity entity = EntityTable.FirstOrDefault(LinqExpression(id));

            return entity;
        }

        public TEntity AddNew(TEntity entity)
        {
            EntityTable.Add(entity);
            SaveDb();
            return entity;
        }

        public TEntity Update(TEntity entity)
        {
            _appDb.Update(entity);
            SaveDb();
            return entity;
        }

        public bool Delete(int id)
        {
            var entity = EntityTable.FirstOrDefault(LinqExpression(id));
            if (entity != null)
            {
                EntityTable.Remove(entity);
                SaveDb();
                return true;
            }
            else return false;
        }

        public void SaveDb()
        {
            _appDb.SaveChanges();
        }
    }
}