MySQL获得第一行值

Question

我的整个查询与此子查询不同：

"(SELECT a.NumSeats From Aircrafts a WHERE f.AircraftID =a.AircrafID)"

我想要返回一个数字，例如5

当我选择a.NumSeats这是一个整数时，我无法理解为什么这不起作用。

此查询也会返回1行的MAX。

$subQuery1 = "(SELECT COUNT(*) from Seats s WHERE s.FlightID = f.FlightID)";
    $subQuery2 = "(SELECT a.NumSeats From Aircrafts a WHERE f.AircraftID =a.AircrafID)";
    $subQuery2 = 0;
    $query = mysql_query("SELECT * FROM Flights f WHERE f.DeptAirport = '".$dep."' AND f.ArrAirport = '".$arr.
            "' AND f.Date=STR_TO_DATE('".$depDate."', '%Y-%m-%d') AND ".$subQuery1. "=" .$subQuery2);

如果我删除$ subQuery2 = 0则会中断

Answer 1

我认为a.AircrafID应为a.AircraftID。