将mysql行转换为列

Question

I have a table that has a status column, the status is a number between 1-8.

I can use the query

SELECT status, COUNT(id) AS total 
FROM cart_orders 
GROUP BY status;

To get a result that looks like:

status | total
1      | 10
2      | 15
3      | 8
4      | 51
5      | 65 
...

But that means every time I need the data I have to do:

$status = array(1 => null, 2 => null, 3 => null, 4 => null, 
                5 => null, 6 => null, 7 => null, 8 => null);

foreach($rows as $row){
    $status[$row['status']] = $row['total'];
}

Which, while not a lot of code I would like to avoid having to do that,

What I want is to modify the query so I end up with a single row that looks like:

1  | 2  | 3  | 4  | 5   
10 | 15 | 8  | 51 | 65 ...

so I can just go e.g. $row['4']

The only what I can think of to do this would be to have each column as a subquery, which I would rather use the code than have 8 sub-queries. The other option is to join the table on itself 7 times, but that is assumedly also not ideal?

How else could I do this?

Answer 1

What you are asking to do is called a "pivot query," which MySQL unfortunately does not support natively. What you must do is specify each row individually, as in:

SELECT
   SUM(IF (status = 1, total, 0)) AS '1'
   ...

..but this is very verbose -- especially if you have a lot of columns. I think your PHP is a little more verbose than it needs to be too in that you don't need to declare the array ahead of time.