JSON Encode not giving out right json string

I am trying to echo a json string in PHP which retrieves data from mySql database Bt when i validate json string in JSONlint it gives error:

Parse error on line 4:
...placesname": "abc"}{    "0": "abc",  
----------------------^
Expecting 'EOF', '}', ',', ']'

And my PHP code is:

$query  = mysql_query("SELECT placesname FROM Places;");

while ($row = mysql_fetch_array($query)){
    echo json_encode($row);
}

You're appending all your rows together into one string. You need to make an array of your rows, and then json_encode the array.

You're creating JSON like this:

{"key": "value", "key2": "value2"}{"key": "value", "key2": "value2"}{"key": "value", "key2": "value2"}

Which isn't valid JSON. It needs to look like this:

[
  {"key": "value", "key2": "value2"},
  {"key": "value", "key2": "value2"},
  {"key": "value", "key2": "value2"}
]

which is what you'll get if you json_encode an array of objects.

I'm not a PHP expert, but try something along these lines:

$query  = mysql_query("SELECT placesname FROM Places;");

$rows = Array();
while ($row = mysql_fetch_array($query)){
  $rows[] = $row;
}

echo json_encode($rows);

Try this..

$query  = mysql_query("SELECT placesname FROM Places;");
$data = array();
while ($row = mysql_fetch_array($query)){
    $data[]=$row['placesname'];
}

echo json_encode($data);