Захват счета из SQL-запроса

Ответ 1

Используйте SqlCommand.ExecuteScalar() и нарисуйте его на int:

cmd.CommandText = "SELECT COUNT(*) FROM table_name";
Int32 count = (Int32) cmd.ExecuteScalar();

Ответ 2

SqlConnection conn = new SqlConnection("ConnectionString");
conn.Open();
SqlCommand comm = new SqlCommand("SELECT COUNT(*) FROM table_name", conn);
Int32 count = (Int32) comm .ExecuteScalar();

Ответ 3

Вы получите ошибки преобразования с помощью

cmd.CommandText = "SELECT COUNT(*) FROM table_name";
Int32 count = (Int32) cmd.ExecuteScalar();

используйте

        string stm = "SELECT COUNT(*) FROM table_name WHERE id="+id+";" ;
        MySqlCommand cmd = new MySqlCommand(stm, conn);
        Int32 count = Convert.ToInt32(cmd.ExecuteScalar());
        if(count > 0){
            found = true ; 
        } else {
            found = false ; 
        }

Ответ 4

Дополнение к С# с помощью SQL:

SqlConnection conn = new SqlConnection("ConnectionString");
        conn.Open();
        SqlCommand comm = new SqlCommand("SELECT COUNT(*) FROM table_name", conn);
        Int32 count = Convert.ToInt32(comm.ExecuteScalar());
        if (count > 0)
        {
            lblCount.Text = Convert.ToString(count.ToString()); //For example a Label
        }
        else
        {
            lblCount.Text = "0";
        }
        conn.Close(); //Remember close the connection