SqlCeDataReader参数ordinal = 1

如何解决SqlCeDataReader参数ordinal = 1

| 我在此代码上出现一个参数序号= 1错误。 有人可以在这种情况下解释吗？ dbCon是正确的，因为我可以尝试将数据取回数据库就可以将数据插入数据库。

              if (dbCon.State == ConnectionState.Closed)
            {
                dbCon.Open(); ;
            }

            SqlCeParameter vetidfromdropbox = new SqlCeParameter(\"@vetidfromdropbox\",SqlDbType.Int);
            vetidfromdropbox.Value = 2;

            SqlCeCommand mySQLCommand = new SqlCeCommand(\"SELECT * FROM vets WHERE vetID = @vetidfromdropbox\",dbCon);

            SqlCeDataReader rdata = mySQLCommand.ExecuteReader();


            if(rdata.Read()){

                    editNameTextbox.Text = (String)rdata[\"vetName\"];
                    editSurnameTextbox.Text = (String)rdata[\"vetSurname\"];
                    editCompanyNameTextbox.Text = (String)rdata[\"vetCompanyName\"];
                    editPractiseAddTextBox.Text = (String)rdata[\"vetPractiseAddress\"];
                    editMobileTextbox.Text = (String)rdata[\"vetMobile\"];
                    editOtherTextbox.Text = (String)rdata[\"vetOther\"];
                    editNotesTextbox.Text = (String)rdata[\"vetNotes\"];

                }else{
                        MessageBox.Show(\" There has been an error with Read() \");                               
                }



            if (dbCon.State == ConnectionState.Open)
            {
                dbCon.Close();
            }

    

解决方法

        您没有在SQL命令中添加参数：

var vetidfromdropbox = new SqlCeParameter(\"@vetidfromdropbox\",SqlDbType.Int);
vetidfromdropbox.Value = 2;

var mySQLCommand = new SqlCeCommand(
    \"SELECT * FROM vets WHERE vetID = @vetidfromdropbox\",dbCon);
mySQLCommand.Parameters.Add(vetidfromdropbox);

您可以使用AddWithValue简化语法：

var mySQLCommand = new SqlCommand(
    \"SELECT * FROM vets WHERE vetID = @vetidfromdropbox\",dbCon);
mySQLCommand.Parameters.AddWithValue(\"vetidfromdropbox\",2);

旁注：在您的sql连接和命令上使用guarantee3ѭ保证处理并简化代码。