谁能告诉我这个更新声明有什么问题？ 访问数据库

Question

private void btnUpdate_Click(object sender, EventArgs e)
{
    try
    {
            using (OleDbConnection conn = new OleDbConnection(Con))
            {
                conn.Open();

                OleDbCommand cmd = new OleDbCommand("UPDATE ACTB SET FirstName = @FirstName, LastName = @LastName, GrossIncome = @GrossIncome, LessTNT = @LessTNT,  TaxableIncomeCE = @TCI, " +
                                                                    "TaxableIncomePE = @ADDTI, GrossTaxableIncome = @GTI, LessTE = @LessTE, LessPPH = @LessPPH, NetTax = @LessNTI," +
                                                                    "TaxDue = @TD, HeldTaxCE = @TWCE, HeldTaxPE = @TWPE, TotalTax = @TATW WHERE ID = @ID", conn);

                // OleDbCommand cmd = new OleDbCommand("UPDATE ACTB SET (FirstName, LastName, GrossIncome, LessTNT, TaxableIncomeCE, TaxableIncomePE, GrossTaxableIncome, LessTE, LessPPH, NetTax, TaxDue, HeldTaxCE, HeldTaxPE, TotalTax) = " +
                // "VALUES(@FirstName, @LastName, @GrossIncome, @LessTNT, @TCI, @ADDTI, @GTI, @LessTE, @LessPPH, @LessNTI, @TD, @TWCE, @TWPE, @TATW)", conn);
                cmd.Parameters.AddWithValue("@ID", txtID.Text);
                cmd.Parameters.AddWithValue("@FirstName", txtFirst.Text);
                cmd.Parameters.AddWithValue("@LastName", txtLast.Text);
                cmd.Parameters.AddWithValue("@GrossIncome", Convert.ToDouble(txtGross.Text));
                cmd.Parameters.AddWithValue("@LessTNT", Convert.ToDouble(txtLessTNT.Text));
                cmd.Parameters.AddWithValue("@TCI", Convert.ToDouble(txtTCI.Text));
                cmd.Parameters.AddWithValue("@ADDTI", Convert.ToDouble(txtADDTI.Text));
                cmd.Parameters.AddWithValue("@GTI", Convert.ToDouble(txtGTI.Text));
                cmd.Parameters.AddWithValue("@LessTE", Convert.ToDouble(txtLessTE.Text));
                cmd.Parameters.AddWithValue("@LessPPH", Convert.ToDouble(txtLessPPH.Text));
                cmd.Parameters.AddWithValue("@LessNTI", Convert.ToDouble(txtLessNTI.Text));
                cmd.Parameters.AddWithValue("@TD", Convert.ToDouble(txtTD.Text));
                cmd.Parameters.AddWithValue("@TWCE", Convert.ToDouble(txtTWCE.Text));
                cmd.Parameters.AddWithValue("@TWPE", Convert.ToDouble(txtTWPE.Text));
                cmd.Parameters.AddWithValue("@TATW", Convert.ToDouble(txtTATW.Text));
                cmd.ExecuteNonQuery();
                conn.Close();
            }
    }
    catch (OleDbException ex)
    {
        MessageBox.Show(ex.Message);
    }
    finally
    {
        lblSuccess.Text = "Successfully updated the records!";
        Restore();
    }
}

Been looking for something wrong with this but I can't find it. It doesn't update the table which Restore() handles btw. No errors are thrown.

Though it did have a "Connection string not properly initialized" and error in update statement errors earlier.

Answer 1

OleDbCommand doesn't have the concept of Name value parameters. So you MUST define them in the same order as in the query.

So first parameter should be

cmd.Parameters.AddWithValue("@FirstName", txtFirst.Text);
cmd.Parameters.AddWithValue("@LastName", txtLast.Text);
//and so on ...

//last one
cmd.Parameters.AddWithValue("@ID", txtID.Text);

Also you can use @ to write strings on multiple lines.

PS There is no need to Close() the connection when you use using, this is done automatically by Dispose()