Convert PHP Multi-Dimensional Array to Postgres HStore

If you're interested in converting a PHP array to a PostgreSQL Hstore Array (data type: hstore[]), then PHPG's Utils class does the trick (disclaimer: I'm the maintainer of that project):

PHP Array of Associative Arrays to PostgreSQL Hstore Array:

<?php
include 'phpg_utils.php';

$array = array(
  array(
    'name' => 'John',
    'age' => 32
  ),
  array(
    'name' => 'Jane',
    'age' => 28
  )
);

$hstore_array = PHPG_Utils::hstoreFromPhp($array, True);
print $hstore_array;

// Outputs:
//   {"\"name\"=>\"John\",\"age\"=>\"32\"","\"name\"=>\"Jane\",\"age\"=>\"28\""} 

// You can then directly insert this into the database:
pg_query("INSERT INTO my_table (hstore_arr_col) VALUES ('" . pg_escape_string($hstore_array) . "')");

PHP Associative Array to PostgreSQL Hstore:

$array = array(
    'name' => 'John',
    'age' => 32
);

$hstore = PHPG_Utils::hstoreFromPhp($array);
print $hstore ;

// Outputs:
//   "name"=>"John","age"=>"32"

// You can then directly insert this into the database:
pg_query("INSERT INTO my_table (hstore_col) VALUES ('" . pg_escape_string($hstore) . "')");

UPDATE:

In a PostgreSQL 9.4+ world, I'd highly recommend using PostgreSQL's JSONB data-type rather than HSTORE. This allows you to easily encode PHP associative arrays to JSON, and vice versa. This means no special libraries, and official support across the board.