我在阅读器中遇到一个问题。我的代码部分表示输入的格式不正确，但是自阅读器后返回了一行.HasRows返回true ..
我也在谷歌搜索过这个，并了解到转换可能是问题所在。但是，这对我来说可能不是问题，因为代码以前工作过，现在我遇到了这个问题。
这怎么可能？可能是什么问题呢？提前致谢..
这是堆栈跟踪： StackTrace“at System.Number.StringToNumber（String str，NumberStyles options，NumberBuffer＆number，NumberFormatInfo info，Boolean parseDecimal）\ r \ n在System.Number.ParseInt32（String s，NumberStyles style，NumberFormatInfo info）\ r \ n在MySql .Data.Types.MySqlInt32.MySql.Data.Types.IMySqlValue.ReadValue（MySqlPacket数据包，Int64长度，布尔nullVal）\ r \ n在MySql.Data.MySqlClient.NativeDriver.ReadColumnValue（Int32索引，MySqlField字段，IMySqlValue valObject） \ r \ n at MySql.Data.MySqlClient.ResultSet.ReadColumnData（Boolean outputParms）\ r \ n at MySql.Data.MySqlClient.ResultSet.NextRow（CommandBehavior behavior）\ r \ n at MySql.Data.MySqlClient.MySqlDataReader.Read （）\ r \ n在System.Data.Common.DbEnumerator.MoveNext（）\ r \ n at System.Linq.SystemCore_EnumerableDebugView.get_Items（）“string
这是我的代码：
class ControlDB
{
MySqlConnection connection;
MySqlDataAdapter adapter;
MySqlCommand command;
DataTable dataTable;
MySqlDataReader reader;
private string server;
private string database;
private string userid;
private string password;
public ControlDB()
{
ConnectDB();
}
public void ConnectDB()
{
server = "localhost";
database = "YBHDB";
userid = "root";
password = "";
string connectionString = "SERVER=" + server + ";" + "DATABASE=" + database + ";" + "UID=" + userid + ";" + "PASSWORD=" + password + ";";
connection = new MySqlConnection(connectionString);
connection.Open();
}
public string[] GetCustomer(string arrivalDate, string arrivalTime, string departureDate, string departureTime, string roomId)
{
string[] customer = new string[20];
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.Append("SELECT c.FirstName, c.MiddleName, c.LastName, c.Address, c.Nationality, c.ContactNumber, c.Email, c.CustomerID, rc.RoomId, rc.RCID, rc.ArrivalDate, rc.DepartureDate, rc.ArrivalTime, rc.DepartureTime, rc.DaysOfStay, rc.NumberOfAdult, rc.NumberOfChildren, rc.PaymentType, rc.CardType, rc.CardNumber ");
stringBuilder.Append("FROM customer c JOIN reservationcheckin rc ON ");
stringBuilder.Append("c.CustomerId = rc.CustomerID ");
stringBuilder.Append("WHERE ((concat(rc.ArrivalDate, ' ', rc.ArrivalTime) BETWEEN concat(@arrivalDT, ' ', @arrivalTM) AND concat(@departureDT, ' ', @departureTM) ");
stringBuilder.Append("OR concat(rc.DepartureDate, ' ', rc.DepartureTime) BETWEEN concat(@arrivalDT, ' ', @arrivalTM) AND concat(@departureDT, ' ', @departureTM)) ");
stringBuilder.Append("OR (concat(@arrivalDT, ' ', @arrivalTM) BETWEEN concat(rc.ArrivalDate, ' ', rc.ArrivalTime) AND concat(rc.DepartureDate, ' ', rc.DepartureTime) ");
stringBuilder.Append("OR concat(@departureDT, ' ', @departureTM) BETWEEN concat(rc.ArrivalDate, ' ', rc.ArrivalTime) AND concat(rc.DepartureDate, ' ', rc.DepartureTime)) ) ");
stringBuilder.Append("AND rc.RoomId = @roomId");
command = new MySqlCommand();
command.Connection = connection;
command.CommandText = stringBuilder.ToString();
MySqlParameter arrivalDateParameter = new MySqlParameter("@arrivalDT", Convert.ToDateTime(arrivalDate).Date.ToString("yyyy-MM-dd"));
MySqlParameter arrivalTimeParameter = new MySqlParameter("@arrivalTM", (Convert.ToDateTime(arrivalTime).TimeOfDay).ToString().Replace('{', ' ').Trim());
MySqlParameter departureDateParameter = new MySqlParameter("@departureDT", Convert.ToDateTime(departureDate).Date.ToString("yyyy-MM-dd"));
MySqlParameter departureTimeParameter = new MySqlParameter("@departureTM", (Convert.ToDateTime(departureTime).TimeOfDay).ToString().Replace('{', ' ').Trim());
MySqlParameter roomParameter = new MySqlParameter("@roomId", Convert.ToInt32(roomId));
command.Parameters.Add(arrivalDateParameter);
command.Parameters.Add(arrivalTimeParameter);
command.Parameters.Add(departureDateParameter);
command.Parameters.Add(departureTimeParameter);
command.Parameters.Add(roomParameter);
reader = command.ExecuteReader();
if(reader.HasRows)
{
reader.Read();
customer[0] = reader["FirstName"].ToString();
customer[1] = reader["MiddleName"].ToString();
customer[2] = reader["LastName"].ToString();
customer[3] = reader["Address"].ToString();
customer[4] = reader["Nationality"].ToString();
customer[5] = reader["ContactNumber"].ToString();
customer[6] = reader["Email"].ToString();
customer[7] = reader["RoomID"].ToString();
customer[8] = reader["ArrivalDate"].ToString();
customer[9] = reader["ArrivalTime"].ToString();
customer[10] = reader["DepartureDate"].ToString();
customer[11] = reader["DepartureTime"].ToString();
customer[12] = reader["DaysOfStay"].ToString();
customer[13] = reader["NumberOfAdult"].ToString();
customer[14] = reader["NumberOfChildren"].ToString();
customer[15] = reader["PaymentType"].ToString();
customer[16] = reader["CardType"].ToString();
customer[17] = reader["CardNumber"].ToString();
customer[18] = reader["CustomerID"].ToString();
customer[19] = reader["RCID"].ToString();
}
reader.Close();
return customer;
}
}
以下是调用GetCustomer（）的方法：
private void buttons_Click(object sender, EventArgs e)
{
Button button = (Button)sender;
string[] customer = new string[20];
string roomId = button.Text.Split(' ')[1];
customer = control.GetCustomer(arrivalDatePicker.Value.ToShortDateString(), arrivalTimePicker.Value.ToShortTimeString(), departureDatePicker.Value.ToShortDateString(), departureTimePicker.Value.ToShortTimeString(), roomId);
firstNameText.Text = customer[0];
middleNameText.Text = customer[1];
lastNameText.Text = customer[2];
addressText.Text = customer[3];
nationalityText.Text = customer[4];
contactText.Text = customer[5];
emailText.Text = customer[6];
roomNo.Text = customer[7];
arrivalDatePicker.Text = customer[8];
arrivalTimePicker.Text = customer[9];
departureDatePicker.Text = customer[10];
departureTimePicker.Text = customer[11];
daysStay.Text = customer[12];
numAdultText.Text = customer[13];
numChildText.Text = customer[14];
paymentTypeSelect.Text = customer[15];
cardTypeSelect.Text = customer[16];
cardNumberText.Text = customer[17];
customerID = Convert.ToInt32(customer[18]);
roomID = Convert.ToInt32(customer[7]);
rcid = Convert.ToInt32(customer[19]);
}
在调查时，代码在时间部分遇到错误。 SQL中的arrivalTime和departureTime的数据类型是Time，当读者读取行时会遇到问题。所以我只是将我的数据类型更改为varchar。希望这不会在将来导致任何错误.. xx