我正在尝试更新数据，但它不起作用

Question

我做了一个程序，保存和更新数据从Access数据库，我可以保存和读取数据，我也可以更新，但问题是，当我试图更新数据，它去到第二个条件"数据未更新"。我已经添加了我的代码，如果有任何错误请帮我解决。

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.SqlClient;
using System.Data.OleDb;

namespace qasimpos
{
public partial class Form9 : Form
{
string connectionString = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|pos.accdb;Persist Security Info=True";
string nname, ddate, ccompany, pparty, oorder, kkg, PpCS, ppprice, ccprice, wwprice, rrprice, bbilln, qquantity;


private void btnclose_Click(object sender, EventArgs e)
{
this.Close();
}

private void btnup_Click(object sender, EventArgs e)
{
nname = textBox1.Text;
ddate = textBox2.Text;
ccompany = textBox3.Text;
pparty = textBox4.Text;
oorder = textBox5.Text;
kkg = textBox6.Text;
PpCS = textBox7.Text;
ppprice = textBox8.Text;
ccprice = textBox9.Text;
wwprice = textBox10.Text;
rrprice = textBox11.Text;
bbilln = textBox12.Text;
qquantity = textBox13.Text;

//SqlConnection connection = new SqlConnection(connectionString);
OleDbConnection connection = new OleDbConnection(connectionString);
connection.Open();
try
{
string query = "UPDATE prod SET tareekh=@tareekh,company=@company,party=@party,hukam=@hukam,kg=@kg,PCS=@PCS,pprice=@pprice,cprice=@cprice,wprice=@wprice,rprice=@rprice,billn=@billn,quantity=@quantity WHERE namee=@namee";
//SqlCommand cmmd = new SqlCommand(query, connection);
OleDbCommand cmmd = new OleDbCommand(query, connection);
cmmd.Parameters.AddWithValue("@namee", nname);
cmmd.Parameters.AddWithValue("@tareekh", ddate);
cmmd.Parameters.AddWithValue("@company", ccompany);
cmmd.Parameters.AddWithValue("@party", pparty);
cmmd.Parameters.AddWithValue("@hukam", oorder);
cmmd.Parameters.AddWithValue("@kg", kkg);
cmmd.Parameters.AddWithValue("@PCS", PpCS);
cmmd.Parameters.AddWithValue("@pprice", ppprice);
cmmd.Parameters.AddWithValue("@cprice", ccprice);
cmmd.Parameters.AddWithValue("@wprice", wwprice);
cmmd.Parameters.AddWithValue("@rprice", rrprice);
cmmd.Parameters.AddWithValue("@billn", bbilln);
cmmd.Parameters.AddWithValue("@quantity", qquantity);

int result = cmmd.ExecuteNonQuery();
if (result > 0)
{
MessageBox.Show("Data Updated Successfully ");
this.Close();

}
else
{
MessageBox.Show("Data Not Updated");
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
connection.Close();
}


}

private void textBox12_TextChanged(object sender, EventArgs e)
{

}

private void Form9_Load(object sender, EventArgs e)
{
textBox1.Text = nname;
textBox2.Text = ddate;
textBox3.Text = ccompany;
textBox4.Text = pparty;
textBox5.Text = oorder;
textBox6.Text = kkg;
textBox7.Text = PpCS;
textBox8.Text = ppprice;
textBox9.Text = ccprice;
textBox10.Text = wwprice;
textBox11.Text = rrprice;
textBox12.Text = bbilln;
textBox13.Text = qquantity;
}

public Form9(string namee,string tareekh,string company,string party,string hukam,string kg,string PCS,string pprice,string cprice,string wprice,string rprice,string billn,string quantity)
{
InitializeComponent();
nname = namee;
ddate = tareekh;
ccompany = company;
pparty = party;
oorder = hukam;
kkg = kg;
PpCS = PCS;
ppprice = pprice;
ccprice = cprice;
wwprice = wprice;
rrprice = rprice;
bbilln = billn;
qquantity = quantity;
}
}
} 

Answer 1

参数应与查询中的参数相同。

请直接从文档中查找以下内容

OLE DB .NET提供程序不支持命名参数的传递对象调用的SQL语句或存储过程的参数"CommandType"为"Text"时的OleDbCommand。在这种情况下，必须使用问号(?)占位符。例如:SELECT * FROMcustomer WHERE CustomerID = ?因此，其中的顺序OleDbParameter对象必须添加到OleDbParameterCollection中直接对应于问号占位符的位置对于命令文本中的参数。