private static void SaveMunicipalities(DataTable dataTable) { using (var ctx = new MunicipalityDataContext()) { var municipalityMapper = new MunicipalityMapper(dataTable); var municipalityModel = municipalityMapper.Map(); var existingData = ctx.Municipalities.ToList(); foreach (var row in municipalityModel) { bool isexistingMunicipality = existingData.Join(ctx.Taxes, a => a.MunicipalityId, b => b.MunicipalityId, (a, b) => new { ID = a.MunicipalityId }).Any(); if (!isexistingMunicipality) { var municipalities = new Municipalities { Name = row.Name, IsActive = true, Date = row.Date, CreatedDate = DateTime.Now, ModifiedDate = DateTime.Now }; ctx.Add(municipalities); } } ctx.SaveChanges(); } }