Fix PDO parameter names

[alshayed]

It appears that PDO only allows alphanumeric and underscore characters ([a-zA-Z0-9_]) for placeholder parameter names. However, the zend-db pdo driver just passes on anything without regard to those limitations. This patch addresses that by replacing any non-allowable characters with an underscore.

This is needed because various databases you might access through the PDO driver support more characters than that unquoted. For example MySQL also supports a dollar sign ($) and DB2 on the IBM i (I'm using this via PDO ODBC) supports the dollar sign and the hash/pound sign (#). (Side note - it works fine using the IbmDb2 driver which does positional parameters, but that is only available if you have that built in to PHP and are running it directly on the DB2 server or have purchased DB2 Connect)

I believe this addresses issue #35 though obviously not by changing to positional parameters as suggested there.

[alshayed]

I'm not really sure how to add the tests to exercise this through the database. If somebody would be willing to turn this into the proper test code I would really appreciate it.

Here's how you can prove it manually with PDO/MySQL:

CREATE TABLE test001 (
id integer not null auto_increment,
text_ char(10),
text$ char(10),

primary key (id)
);

Then example PHP in the root directory:

<?php

require __DIR__ . '/vendor/autoload.php';

$db_options = [
    'driver' => 'pdo',
    'dsn' => 'mysql:host=YOUR_DB_HOST;dbname=YOUR_DB_NAME;charset=utf8',
    'user' => 'YOUR_DB_USER',
    'pass' => 'YOUR_DB_PASS',
];

$db = new \Zend\Db\Adapter\Adapter($db_options);

$test001 = new \Zend\Db\TableGateway\TableGateway('test001', $db);
$test001->insert([
    'text_' => 'hi',
    'text$' => 'dude',
]);

$rowset = $test001->select();

$count = 0;
foreach ($rowset as $row) {
    $count++;
    echo json_encode($row) . PHP_EOL;
}

echo PHP_EOL . "found " . $count . " row(s)" . PHP_EOL;

So if you run it against the current master branch it fails with an exception, but my changes make it work as expected.

[ezimuel]

I don't think the approach of this PR is correct, in order to fix #35 we need to work on Zend\Db\Adapter\Driver\Pdo\Pdo::formatParameterName() and Zend\Db\Adapter\Driver\Pdo\Statement::bindParametersFromContainer(). I'm working on a new PR to address this.

[ezimuel]

This replace can produce conflicts in bindParam name. For instance, if you have 2 fields text- and text$ they will be replaced with text_ and text_ both.

[ezimuel]

Closing this in favor of #224