c# - if (计数器==<数据库值>)

Question

如何将数据库中的值转换为可用于 if else 函数的 int 值？

例如:在我的数据库“armnumber = 3”中，如何在 if else 函数中使用它？

代码

string myConnectionString;
myConnectionString = "server=localhost;uid=root;pwd=root;database=medicloud;SslMode=None;charset=utf8";

try
{
    MySqlConnection connection = new MySqlConnection(myConnectionString);
    MySqlCommand cmd = new MySqlCommand();

    cmd.CommandType = CommandType.Text;
    string sqlStr = "Select armnumber from assign where id=1";
    cmd.CommandText = sqlStr;
    cmd.Connection = connection;

    connection.Open();
    cmd.ExecuteNonQuery();
}

catch (MySqlException ex)
{
}
#endregion
if (counter == )
{
}

Answer 1

一个选项是 MySqlDataAdapter像这样:

MySqlDataAdapter da = new MySqlDataAdapter {SelectCommand = cmd};
DataSet ds = new DataSet();
int armnumber = da.Fill(ds);
...
if (counter == armnumber)

此外，您应该始终使用 parameterized queries避免SQL Injection :

string sqlStr = "Select armnumber from assign where id=@id"; 
cmd.Parameters.AddWithValue("@id", 1);
//Or better
cmd.Parameters.Add("@id", SqlDbType.Int).Value = 1;