PHP script not indexing my PostgreSQL array properly

Question

I'm facing a problem with reading an associative array from an SQL query on my PostgreSQL database.

So here's my database:

ID | NAME | ....
1  | CARS | 
2  | BIKES| 
3  | TRAINS |

Now I have a PHP script that I want to grab some data from that query and encode it into JSON for a mobile device.

Here is the script:

    $res = pg_query("SELECT * FROM projects");

/* FETCHES THE RESULT OF THE SQL QUERY WHICH GETS THE NAME OF EACH PROJECT */
while($row = pg_fetch_assoc($res))
{
    $output[]=$row['name'];
    print (json_encode($output));
}  /* CONVERTED ON MOBILE PLATFORM */

pg_close(); 

Now the result I'm getting is shown copy and pasted from the output of the file (below):

["Cars"]["Cars","Bikes"]["Cars","Bikes","Trains"]

I can clearly see that my algorithm is indexing the records is a sort of 1, 1,2, 1,2,3 kind of way. Has anyone got any advice on how to solve this and to get this output:

["Cars"]["Bikes"]["Trains"]

Answer 1

You should just print the array at the end, after it was fully populated:

$res = pg_query("SELECT * FROM projects");

/* FETCHES THE RESULT OF THE SQL QUERY WHICH GETS THE NAME OF EACH PROJECT */
while($row = pg_fetch_assoc($res))
{
    $output[]=$row['name'];
}  /* CONVERTED ON MOBILE PLATFORM */

print (json_encode($output));

pg_close();

Alternatively, you could reinitialize the $output array if you need to output the individually. Depends on what you want to achieve:

$res = pg_query("SELECT * FROM projects");

/* FETCHES THE RESULT OF THE SQL QUERY WHICH GETS THE NAME OF EACH PROJECT */
while($row = pg_fetch_assoc($res))
{
    $output = array();
    $output[]=$row['name'];
    print (json_encode($output));
}  /* CONVERTED ON MOBILE PLATFORM */

pg_close();