Description:
------------
The "sql_field_string" defined in "sphinx.conf" does not return the expected string but return a number instead. But it work if I use "search.exe" tool in cli mode or the "sphinxapi.php" provided in sphinx package.

Used Versions :
- PHP : 5.4.16 (Wampserver 2.4)
- sphinx : Sphinx 2.1.9-release (r4761)
- pecl sphinx : 1.3.2 & 1.3.1 (5.4 Thread Safe (TS) x86)

Test script:
---------------
- In "sphinx.conf" :

source documents : base 
{
   ....
   sql_query 	    = SELECT `id`, `title` FROM `documents`
   sql_field_string = title
}

index documents 
{
  source = documents
  path = C:\Sphinx\var\data\documents
  dict = keywords
  min_infix_len = 3
  charset_type = utf-8
}

-> I use the "example.sql" in the sphinx package. 

// In "sphinx_test.php" :

$s = new SphinxClient();
$s->setServer("localhost", 9312);
$result = $s->query('test', 'documents');
print_r($result);

Expected result:
----------------
Array
(
    [error] => 
    [warning] => 
    [status] => 0
    [fields] => Array
        (
            [0] => title
        )

    [attrs] => Array
        (
            [title] => 7
        )

    [matches] => Array
        (
            [1] => Array
                (
                    [weight] => 1
                    [attrs] => Array
                        (
                            [title] => test one    <------ this one
                        )

                )

            [2] => Array
                (
                    [weight] => 1
                    [attrs] => Array
                        (
                            [title] => test two     <------ this one
                        )

                )

        )

    [total] => 2
    [total_found] => 2
    [time] => 0.015
    [words] => Array
        (
            [test] => Array
                (
                    [docs] => 2
                    [hits] => 2
                )

        )

)


Actual result:
--------------
Array
(
    [error] => 
    [warning] => 
    [status] => 0
    [fields] => Array
        (
            [0] => title
        )

    [attrs] => Array
        (
            [title] => 7
        )

    [matches] => Array
        (
            [1] => Array
                (
                    [weight] => 1
                    [attrs] => Array
                        (
                            [title] => 46017541   <--------
                        )

                )

            [2] => Array
                (
                    [weight] => 1
                    [attrs] => Array
                        (
                            [title] => 46017561 <-------------
                        )

                )

        )

    [total] => 2
    [total_found] => 2
    [time] => 0
    [words] => Array
        (
            [test] => Array
                (
                    [docs] => 2
                    [hits] => 2
                )

        )

)