Check And Update On datable

Check data FirstOrDefault And LastOrDefault

foreach (DataGridViewRow dgvR in this.dgvExcel.Rows) {     string Check="",EmpOrg;     Check = string.Format("EmpKey = {0} ", dgvR.Cells[dgvExcel.Columns["EmpKey"].Index].Value);     EmpOrg = dgvR.Cells[dgvExcel.Columns["OrganizationKey"].Index].Value.ToString();     drCheck = this._dsData.Tables[this._sqlManager.TableNameEmployee].Select(Check).FirstOrDefault();     if (drCheck != null)     {         drCheck["OrganizeKey"] = EmpOrg;     }     drCheck = this._dsData.Tables[this._sqlManager.TableNameEmployeeEvents].Select(Check).LastOrDefault();     if (drCheck != null)     {          drCheck["OrganizeKey"] = EmpOrg;     } }