زیر برنامه ی زیر برای اضافه کردن یک رکورد به database می باشد و با هر بار اجرا تنها یک رکورد به database اضافه می کند و چنانچه بخواهم رکورد دیگری اضافه کنم با Error مواجه می شوم و عمل درج رکورد دوم صورت نمی گیره مگر اینکه دوباره برنامه رو Run کنم.
کسی می دونه علت چیه؟
کسی می تونه کمک کنه؟
خیلی ممنون می شم اگه راهنمایی کنید.
Error: the variable named ‘@Id’ has already been declared. Variable names must be uniqe within a query batch or store procedure.
namespace Company
{
public partial class FrmAddAluminium : Form
{
const string _connectionString="server=localhost ; database=Company ; uid=sa ; pwd=sprt&&1363 ";
const string _commandText = "SELECT * " +
"FROM AluminiumBuyTbl "+
"JOIN Person ON AluminiumBuyTbl.Id=Person.Id ";
SqlConnection objConnection = new SqlConnection(_connectionString);
SqlCommand objCommand = new SqlCommand();
SqlDataAdapter objDataAdapter = new SqlDataAdapter(_commandText, _connectionString);
DataSet objDataSet ;
DataView objDataView;
public FrmAddAluminium()
{
InitializeComponent();
}
private void FrmAddAluminium_Load(object sender, EventArgs e)
{
FillDatasetAndDataview();
BindingData();
}
private void FillDatasetAndDataview()
{
objDataSet = new DataSet();
objDataAdapter.Fill(objDataSet, "AluminiumBuyTbl");
objDataView = new DataView(objDataSet.Tables["AluminiumBuyTbl"]);
}
private void BindingData()
{
txtOnUnitCost.DataBindings.Clear();
txtSalesMan.DataBindings.Clear();
txtSumPrice.DataBindings.Clear();
txtWeight.DataBindings.Clear();
txtOnUnitCost.DataBindings.Add("Text", objDataView, "OnUnitCost");
txtSalesMan.DataBindings.Add("Text", objDataView, "SalesMan");
txtSumPrice.DataBindings.Add("Text", objDataView, "SumPrice");
txtWeight.DataBindings.Add("Text", objDataView, "Weight");
}
private void btnAdd_Click(object sender, EventArgs e)
{
Int16 result;
SqlCommand maxIdCommand = new SqlCommand( "SELECT MAX(Id) " +
"FROM AluminiumBuyTbl ", objConnection);
objConnection.Open();
object maxId = maxIdCommand.ExecuteScalar();
int intmaxId = (int)maxId;
string str = (intmaxId+1).ToString();
objCommand.Connection = objConnection;
objCommand.CommandType = CommandType.Text;
objCommand.CommandText = "INSERT INTO AluminiumBuyTbl " +
"(Id ,SalesMan ,OnUnitCost ,Weight ,SumPrice) " +
"VALUES (@Id ,@SalesMan ,@OnUnitCost ,@Weight ,@SumPrice) ";
objCommand.Parameters.AddWithValue("@Id", str).DbType = DbType.Int16 ;
objCommand.Parameters.AddWithValue("@SalesMan", txtSalesMan.Text);
objCommand.Parameters.AddWithValue("@OnUnitCost", txtOnUnitCost.Text).DbType = DbType.Currency;
objCommand.Parameters.AddWithValue("@Weight", txtWeight.Text);
objCommand.Parameters.AddWithValue("@SumPrice", txtSumPrice.Text).DbType=DbType.Currency ;
try
{
objCommand.ExecuteNonQuery();
}
catch (Exception Err)
{
MessageBox.Show(Err.Message);
}
objConnection.Close();
FillDatasetAndDataview();
BindingData();
//Clear frmAddAluminium
txtOnUnitCost.Text = "";
txtSalesMan.Text = "";
txtSumPrice.Text = "";
txtWeight.Text = "";
}
}
}
Error: the variable named ‘@Id’ has already been declared. Variable names must be uniqe within a que
پاسخ با نقل قول
