mysql c＃命令執行期間遇到致命錯誤

Question

我在C＃中的MySQL期間遇到問題。 我想在我的MySQL數據庫中搜索4個關鍵字，當我找到一個條目時，我的WPF程序在列表視圖中顯示它，但我總是得到一個：

命令執行期間遇到致命錯誤

這是我的代碼：

    private void Button_Click(object sender, RoutedEventArgs e)
    {

        string strName = name.Text;
        string strVorname = vorname.Text;
        string strPLZ = plz.Text;
        string strOrt = ort.Text;

        try
        {


            MySqlConnection con = new MySqlConnection(@"Server=xx.xxx.xxx.xx;Uid=user;Pwd=pw;Database=db;");
            con.Open();
            MySqlCommand cmd = new MySqlCommand("SELECT Name, Vorname, Plz, FROM TBCustomer WHERE Name LIKE @strName AND Vorname LIKE @strVorname AND Plz LIKE @strPLZ", con);

            cmd.Parameters.AddWithValue( "@Name", String.Format( "%{0}%", strName));
            cmd.Parameters.AddWithValue( "@Vorname", String.Format( "%{0}%", strVorname));
            cmd.Parameters.AddWithValue("@Plz", String.Format("%{0}%", strPLZ));

            using (var reader = cmd.ExecuteReader())
            {    
                while (reader.Read())//Lese alle Datensätze aus
                {
                    var getName = reader.GetString(reader.GetOrdinal("Name"));  // 'String aus der Spalte "Name" auslesen
                    MessageBox.Show(getName);                                                         
                }

            }



            con.Close();
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }

Answer 1

用這個

MySqlCommand cmd = new MySqlCommand("SELECT Name, Vorname, Plz FROM TBCustomer WHERE Name LIKE @strName AND Vorname LIKE @strVorname AND Plz LIKE @strPlz", con);
cmd.Parameters.AddWithValue( "@strName", String.Format( "%{0}%", strName));
cmd.Parameters.AddWithValue( "@strVorname", String.Format( "%{0}%", strVorname));
cmd.Parameters.AddWithValue("@strPlz", String.Format("%{0}%", strPLZ));

注意：未被'包圍的參數對於將其視為參數是正確的。

去除,從查詢（后PLZ）！ 真是瘋了。

Answer 2

檢查參數名稱：您可以像這樣更改代碼段：

 MySqlCommand cmd = new MySqlCommand("SELECT Name, Vorname, Plz, FROM TBCustomer WHERE Name LIKE '@Name' AND Vorname LIKE '@Vorname' AND Plz LIKE '@Plz' ", con);

            cmd.Parameters.AddWithValue( "@Name", String.Format( "%{0}%", strName));
            cmd.Parameters.AddWithValue( "@Vorname", String.Format( "%{0}%", strVorname));
            cmd.Parameters.AddWithValue("@Plz", String.Format("%{0}%", strPLZ));