我在 mysql 數(shù)據(jù)庫(kù)中有兩個(gè)時(shí)間字段。我需要在添加新時(shí)間之前進(jìn)行檢查，我嘗試使用此代碼。private bool TimeFound(){    MySqlConnection cnn = new MySqlConnection(DB.GetCS("127.0.0.1", "3306",        "db", "root", "password", "utf8"));    string query = "SELECT time.From, time.To FROM db.time WHERE " +        "(time.From, time.To) NOT IN (SELECT time.From, time.To FROM db.time " +        "WHERE (time.From = @From AND time.To = @To";    cnn.Open();    MySqlCommand command = new MySqlCommand(query, cnn);    command.Parameters.AddWithValue("@From", dateTimePicker1.Value.ToString("HH:mm:ss"));    command.Parameters.AddWithValue("@To", dateTimePicker2.Value.ToString("HH:mm:ss"));    object result = command.ExecuteScalar();    if (result == null)    {        return false;    }    else    {        return true;    }}每次我嘗試調(diào)用該函數(shù)時(shí)，我都會(huì)在這一行出錯(cuò)。object result = command.ExecuteScalar();MySql.Data.MySqlClient.MySqlException: '你的 SQL 語(yǔ)法有錯(cuò)誤；檢查與您的 MySQL 服務(wù)器版本相對(duì)應(yīng)的手冊(cè)，了解在第 1 行附近使用的正確語(yǔ)法