[英]Query on Mysql database with asp.net core
我需要查詢數據庫。 該查詢工作正常,但是我需要循環讀取表中的所有數據。 我不知道如何在此查詢中添加“做”或“在”時
[HttpPost]
public IActionResult SendMessage(string send_to, string message, string phone)
{
var email = HttpContext.Session.GetString("email");
MySqlDataReader reader;
try
{
cmdMySQL.Connection = conMySQL;
conMySQL.Open();
cmdMySQL.CommandText = "SELECT * FROM tbl_mensagens WHERE enviado = '" + 0 + "' AND email_usuario = '" + email + "' ";
reader = cmdMySQL.ExecuteReader();
while (reader.Read())
{
var codmsgx ="";
phone = "";
message = "";
codmsgx = reader[0].ToString();
phone = reader[4].ToString();
message = reader[5].ToString();
EnviarMensagem(send_to, message, phone, email, codmsgx);
AtualizarBd(send_to, message, phone, email, codmsgx);
}
reader.Close();
return View();
}
catch (Exception ex) { Debug.WriteLine(ex); return View(); }
finally
{
conMySQL.Close();
}
}
您只得到一行,因為您正在調用reader.Read()
。 每次調用Read()時,閱讀器都會前進到下一行並返回true;否則,返回true。 或者,當閱讀器前進到最后一行時,它返回false。
假設您有一個視圖模型:
public class MensagensViewModel
{
public string Codmsgx { get; set; }
public string Phone { get; set; }
public string Message { get; set; }
}
要從tbl_mensagens
表中獲取List<MensagensViewModel>
數據,您需要手動將訪問的數據保存到mensagens
中,如下代碼所示:
try
{
cmdMySQL.Connection = conMySQL;
cmdMySQL.CommandText = "SELECT * FROM tbl_mensagens WHERE enviado = '" + 0 + "' AND email_usuario = '" + email + "' ";
conMySQL.Open();
reader = cmdMySQL.ExecuteReader();
List<MensagensViewModel> mensagens = new List<MensagensViewModel>();//To save all retrieved data
while (reader.Read())
{
var mensagen = new MensagensViewModel()
{
Codmsgx = reader[0].ToString(),
Phone = reader[4].ToString(),
Message = reader[5].ToString()
};
mensagens.Add(mensagen);
//other logic
}
reader.Close();
return View();
}
catch (Exception ex) { Debug.WriteLine(ex); return View(); }
finally
{
conMySQL.Close();
}
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