MySQL SUM of the total COUNT

Question

Seat Type   Quantity left


Business        23
Economy         27
First           15

            Total quantity left : ?

DBMS = MySQL

I've tried the following SQL which to print the above information

$sql = "SELECT SeatType, COUNT(SeatType)AS quantity
              FROM  seat

              WHERE SeatAvailable = 'Yes'  
              GROUP BY SeatType
              ";

How can i sum up the total quantity left(eg:23+27+25) ? Thx for the help in advanced...

Answer 1

SELECT  COALESCE(SeatType, 'Total quantity left') `Seat Type`, 
        COUNT(SeatType)AS quantity
FROM    seat
WHERE   SeatAvailable = 'Yes'  
GROUP   BY SeatType WITH ROLLUP

• SQLFiddle Demo
• GROUP BY Modifier

Answer 2

Like this:

select sum(quantity_left) SeatsRemaining
from etc