Crazy query help.

[programistas]

hey, thanks in advance if someone can help me

 

x      y      auto

 

 

1      2      a

5      3      b

4      6      c

1      2      d

7      7      e

4      6      f

5      3      b

9      4      h

4      6      f

 

 

I need  query to get from table auto_history(x, y, auto) only these cars,

that are in the same place with other cars

 

 

The result must be :

 

a - because  (it has x=1 and y=2    AND      d has also x=1 and y=2), so they are in the same place

d - because (it has x=1 and y=2  and    a has also x=1 and y=2), so they are in the same place

....

 

so, that's what my sql result must give

a, c, d, f

 

[jcbones]

$table = 'table_name';

$query = "SELECT a.auto FROM $table AS a JOIN $table AS b ON (a.x = b.x AND a.y = b.y AND a.auto != b.auto) ORDER BY a.auto";

[programistas]

Yes, that's cool, I assumed, that it's somehow related to joins, but , from the theory what I read on tutorials, I remember that "we use joins  when we need to work on more than 1 table "., so thank you.