使用c＃在asp.net中更新語句

Question

我正在使用帶有C＃的asp.net作為代碼

   OleDbConnection cn = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\Documents and Settings\CJP\My Documents\Visual Studio 2005\WebSites\NewElligibleSoft\elligiblity.mdb;Persist Security Info=False");
        cn.Open();
        string sql = "UPDATE main SET s_name='"+TextBox1.Text+"',inst_code='"+DropDownList1.SelectedItem+"',ms_oms='"+Label7.Text+"',elligiblity='"+Label12.Text+"',Board='"+DropDownList5.SelectedItem+"',percentage='"+TextBox4.Text+"' WHERE elg_id = '"+DropDownList4.SelectedItem+"'";
        OleDbCommand cmd = new OleDbCommand(sql, cn);
        cmd.ExecuteNonQuery();
        cmd.Dispose();
        cn.Close();
        Response.Write("alert('DATA UPDATED')");

我收到了錯誤

cmd.ExecuteNonQuery();

標准表達式中的數據類型不匹配。

Answer 1

不要像代碼那樣

string connection_string="Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\Documents and Settings\CJP\My Documents\Visual Studio 2005\WebSites\NewElligibleSoft\elligiblity.mdb;Persist Security Info=False";
using(OleDbConnection cn = new OleDbConnection(connection_string))
{
     cn.Open();
     string sql = "UPDATE main SET s_name=?,inst_code=?,ms_oms=?,elligiblity=?,Board=?,percentage=?,amount=? WHERE elg_id =?";

     using(OleDbCommand cmd = new OleDbCommand(sql, cn))
     {
          cmd.Parameters.Add(new OleDbParameter("s_name",TextBox1.Text.Trim()));
          cmd.Parameters.Add(new OleDbParameter("inst_code",DropDownList1.SelectedItem.Value.ToString()));
          cmd.Parameters.Add(new OleDbParameter("ms_oms",Label7.Text.ToString()));
          cmd.Parameters.Add(new OleDbParameter("elligiblity",Label12.Text));
          cmd.Parameters.Add(new OleDbParameter("Board",DropDownList5.SelectedItem.Value.ToString()));
          cmd.Parameters.Add(new  OleDbParameter("percentage",DropDownList5.SelectedItem.Value.ToString()));
          cmd.Parameters.Add(new OleDbParameter(amount",DropDownList5.SelectedItem.Value.ToString()));
          cmd.Parameters.Add(new OleDbParameter("elg_id",DropDownList5.SelectedItem.Value.ToString()));
          cmd.ExecuteNonQuery();
          cn.Close();
     }
}        
 Response.Write("alert('DATA UPDATED')");

Answer 2

你可以嘗試DropDownList1.SelectedItem.Text或DropDownList1.SelectedItem.Value

對於所有DropDownLists，這應該是相同的。

此外，您可能必須將TextBox4轉換為“百分比”的相應數據類型。

假設百分比是雙倍的，你需要類似的東西

Double.Parse(Textbox4.Text)

最后，如果您沒有向查詢發送“字符串”，那么從這些字段中刪除單引號真的很好。 這樣你就不會解析數據但仍會發送字符串信息。

Answer 3

刪除DropDownList4.SelectedItem周圍的單引號。 我敢打賭你的elg_id列是整數或類型的，你給它一個字符串。

話雖如此，如果您提供了錯誤文本，數據庫表結構以及其他一些信息，那么您將會感覺更好，這樣人們就不必閱讀您的想法。

Answer 4

OleDbConnection cn = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\Documents and Settings\CJP\My Documents\Visual Studio 2005\WebSites\NewElligibleSoft\elligiblity.mdb;Persist Security Info=False");
        cn.Open();
        string sql = "UPDATE main SET s_name='" + TextBox1.Text + "',inst_code='" + DropDownList1.SelectedItem.Value.ToString() + "',ms_oms='" + Label7.Text + "',elligiblity='" + Label12.Text + "',Board='" + DropDownList5.SelectedItem.Value.ToString() + "',percentage='" + float.Parse(TextBox4.Text) + "',amount='" + Label10.Text + "' WHERE elg_id = " + DropDownList4.SelectedItem.Value + "";
        OleDbCommand cmd = new OleDbCommand(sql, cn);
        cmd.ExecuteNonQuery();
        cmd.Dispose();
        cn.Close();
        Response.Write("alert('DATA UPDATED')");

Answer 5

這是正確的代碼

OleDbConnection cn = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\Documents and Settings\CJP\My Documents\Visual Studio 2005\WebSites\NewElligibleSoft\elligiblity.mdb;Persist Security Info=False");
        cn.Open();
        string sql = "UPDATE main SET s_name='" + TextBox1.Text + "',inst_code='" + DropDownList1.SelectedItem.Value.ToString() + "',ms_oms='" + Label7.Text + "',elligiblity='" + Label12.Text + "',Board='" + DropDownList5.SelectedItem.Value.ToString() + "',percentage='" + float.Parse(TextBox4.Text) + "',amount='" + Label10.Text + "' WHERE elg_id = " + DropDownList4.SelectedItem.Value + "";
        OleDbCommand cmd = new OleDbCommand(sql, cn);
        cmd.ExecuteNonQuery();
        cmd.Dispose();
        cn.Close();
        Response.Write("alert('DATA UPDATED')");

thanxx