Convert PostgreSQL array to PHP array

If you have PostgreSQL 9.2 you can do something like this:

SELECT array_to_json(pg_array_result) AS new_name FROM tbl1;

The result will return the array as JSON

Then on the php side issue:

$array = json_decode($returned_field);

You can also convert back. Here are the JSON functions page

As neither of these solutions work with multidimentional arrays, so I offer here my recursive solution that works with arrays of any complexity:

function pg_array_parse($s, $start = 0, &$end = null)
{
    if (empty($s) || $s[0] != '{') return null;
    $return = array();
    $string = false;
    $quote='';
    $len = strlen($s);
    $v = '';
    for ($i = $start + 1; $i < $len; $i++) {
        $ch = $s[$i];

        if (!$string && $ch == '}') {
            if ($v !== '' || !empty($return)) {
                $return[] = $v;
            }
            $end = $i;
            break;
        } elseif (!$string && $ch == '{') {
            $v = pg_array_parse($s, $i, $i);
        } elseif (!$string && $ch == ','){
            $return[] = $v;
            $v = '';
        } elseif (!$string && ($ch == '"' || $ch == "'")) {
            $string = true;
            $quote = $ch;
        } elseif ($string && $ch == $quote && $s[$i - 1] == "\\") {
            $v = substr($v, 0, -1) . $ch;
        } elseif ($string && $ch == $quote && $s[$i - 1] != "\\") {
            $string = false;
        } else {
            $v .= $ch;
        }
    }

    return $return;
}

I haven't tested it too much, but looks like it works. Here you have my tests with results:

var_export(pg_array_parse('{1,2,3,4,5}'));echo "\n";
/*
array (
  0 => '1',
  1 => '2',
  2 => '3',
  3 => '4',
  4 => '5',
)
*/
var_export(pg_array_parse('{{1,2},{3,4},{5}}'));echo "\n";
/*
array (
  0 => 
  array (
    0 => '1',
    1 => '2',
  ),
  1 => 
  array (
    0 => '3',
    1 => '4',
  ),
  2 => 
  array (
    0 => '5',
  ),
)
*/
var_export(pg_array_parse('{dfasdf,"qw,,e{q\"we",\'qrer\'}'));echo "\n";
/*
array (
  0 => 'dfasdf',
  1 => 'qw,,e{q"we',
  2 => 'qrer',
)
*/
var_export(pg_array_parse('{,}'));echo "\n";
/*
array (
  0 => '',
  1 => '',
)
*/
var_export(pg_array_parse('{}'));echo "\n";
/*
array (
)
*/
var_export(pg_array_parse(null));echo "\n";
// NULL
var_export(pg_array_parse(''));echo "\n";
// NULL

P.S.: I know this is a very old post, but I couldn't find any solution for postgresql pre 9.2

Reliable function to parse PostgreSQL (one-dimensional) array literal into PHP array, using regular expressions:

function pg_array_parse($literal)
{
    if ($literal == '') return;
    preg_match_all('/(?<=^\{|,)(([^,"{]*)|\s*"((?:[^"\\\\]|\\\\(?:.|[0-9]+|x[0-9a-f]+))*)"\s*)(,|(?<!^\{)(?=\}$))/i', $literal, $matches, PREG_SET_ORDER);
    $values = [];
    foreach ($matches as $match) {
        $values[] = $match[3] != '' ? stripcslashes($match[3]) : (strtolower($match[2]) == 'null' ? null : $match[2]);
    }
    return $values;
}

print_r(pg_array_parse('{blah,blah blah,123,,"blah \\"\\\\ ,{\100\x40\t\daő\ő",NULL}'));
// Array
// (
//     [0] => blah
//     [1] => blah blah
//     [2] => 123
//     [3] =>
//     [4] => blah "\ ,{@@ daőő
//     [5] =>
// )

var_dump(pg_array_parse('{,}'));
// array(2) {
//   [0] =>
//   string(0) ""
//   [1] =>
//   string(0) ""
// }

print_r(pg_array_parse('{}'));
var_dump(pg_array_parse(null));
var_dump(pg_array_parse(''));
// Array
// (
// )
// NULL
// NULL

print_r(pg_array_parse('{または, "some string without a comma", "a string, with a comma"}'));
// Array
// (
//     [0] => または
//     [1] => some string without a comma
//     [2] => a string, with a comma
// )

If you can foresee what kind text data you can expect in this field, you can use array_to_string function. It's available in 9.1

E.g. I exactly know that my array field labes will never have symbol '\n'. So I convert array labes into string using function array_to_string

SELECT 
  ...
  array_to_string( labels, chr(10) ) as labes
FROM
  ...

Now I can split this string using PHP function explode:

$phpLabels = explode( $pgLabes, "\n" );

You can use any sequence of characters to separate elements of array.

SQL:

SELECT
  array_to_string( labels, '<--###DELIMITER###-->' ) as labes

PHP:

$phpLabels = explode( '<--###DELIMITER###-->', $pgLabes );

As @Kelt mentioned:

Postgresql arrays look like this: {1,2,3,4}

You can just simply replace first { and last } with [ and ] respectively and then json_decode that.

But his solution works only for one-dimensional arrays.

Here the solution either for one-dimensional and multidimensional arrays:

$postgresArray = '{{1,2},{3,4}}';
$phpArray = json_decode(str_replace(['{', '}'], ['[', ']'], $postgresArray));  // [[1,2],[3,4]]

To cast back:

$phpArray=[[1,2],[3,4]];
$postgresArray=str_replace(['[', ']'], ['{', '}'], json_encode($phpArray));