Description:
------------
Using PHP 5.2.5 (SQLite 3.4.2) the PHP code below gives the SQLite error SQLITE_SCHEMA (database schema has changed).

According to the SQLite documentation:
"In SQLite version 3, an SQLITE_SCHEMA error can only occur when using the sqlite3_prepare()/sqlite3_step()/sqlite3_finalize()  API to execute SQL, not when using the sqlite3_exec()."
http://www.sqlite.org/faq.html#q15

In the following code I AM getting a SQLITE_SCHEMA error, but I am not using prepared queries.  It would therefore seem that either the version of SQLite I am using breaks the above promise, or the PHP PDO interface is using prepared queries internally.

Reproduce code:
---------------
// Print variable utility
function show($var)
{
	print "<pre>\n";
	print_r( $var );
	print "</pre>\n\n";
}

// Path of database file
$path = '/tmp/pdo-bug.db';

// Create first connection object and create table
$conn_1 = new PDO("sqlite:$path");
$conn_1->exec('CREATE TABLE test1 ( key, value );');

// Fetch list of tables using first connection
$result = $conn_1->query("SELECT name FROM sqlite_master WHERE type='table';");
show($result->fetchAll());

// Create a second PDO connection object to same database file
$conn_2 = new PDO("sqlite:$path");

// Create a second table using second connection
$conn_2->exec('CREATE TABLE test2 ( key2, value2 );');

// Fetch list of tables using first connection
// Print error information if query fails
$result = $conn_1->query("SELECT name FROM sqlite_master;");
if( $result instanceof PDOStatement )
	show( $result->fetchAll() );
else
	show( $conn_1->errorInfo() );

// Remove database file
unlink($path);

Expected result:
----------------
Array
(
    [0] => Array
        (
            [name] => test1
            [0] => test1
        )

)

Array
(
    [0] => Array
        (
            [name] => test1
            [0] => test1
        )

    [1] => Array
        (
            [name] => test2
            [0] => test2
        )

)


Actual result:
--------------
Array
(
    [0] => Array
        (
            [name] => test1
            [0] => test1
        )

)

Array
(
    [0] => HY000
    [1] => 17
    [2] => database schema has changed
)