1.5.1. Getting Started

1.5.1.1. Instantiation

You can instantiate ExtendedPdo so that it uses lazy connection, or you can use DecoratedPdo to decorate an existing PDO instance.

1.5.1.1.1. Lazy Connection Instance

Instantiation is the same as with the native PDO class: pass a data source name, username, password, and driver options. There is one additional parameter that allows you to pass attributes to be set after the connection is made.

use Aura\Sql\ExtendedPdo;

$pdo = new ExtendedPdo(
    'mysql:host=localhost;dbname=test',
    'username',
    'password',
    [], // driver attributes/options as key-value pairs
    []  // queries to execute after connection
);

Whereas the native PDO connects on instantiation, ExtendedPdo does not connect immediately. Instead, it connects only when you call a method that actually needs the connection to the database; e.g., on query().

If you want to force a connection, call the connect() method.

// does not connect to the database
$pdo = new ExtendedPdo(
    'mysql:host=localhost;dbname=test',
    'username',
    'password'
);

// automatically connects
$pdo->exec('SELECT * FROM test');

// explicitly forces a connection
$pdo->connect();

If you want to explicitly force a disconnect, call the disconnect() method.

// explicitly forces disconnection
$pdo->disconnect();

Doing so will close the connection by unsetting the internal PDO instance. However, calling an ExtendedPdo method that implicitly establishes a connection, such as query() or one of the fetch*() methods, will automatically re-connect to the database.

1.5.1.1.2. Decorator Instance

The DecoratedPdo class can be used to decorate an existing PDO connection with the ExtendedPdo methods. To do so, instantiate DecoratedPdo by passing an existing PDO connection:

use Aura\Sql\DecoratedPdo;

$pdo = new PDO(...);
$decoratedPdo = new DecoratedPdo($pdo);

The decorated PDO instance now provides all the ExtendedPdo functionality (aside from lazy connection, which is not possible since the PDO instance by definition has already connected).

Decoration of this kind can be useful when you have access to an existing PDO connection managed elsewhere in your application.

N.b.: The disconnect() method will not work on decorated PDO connections, since DecoratedPdo did not create the connection itself. You will need to manage the decorated PDO instance yourself in that case.

1.5.1.2. Array Quoting

The native PDO quote() method will not quote arrays. This makes it difficult to bind an array to something like an IN (...) condition in SQL. However, ExtendedPdo recognizes arrays and converts them into comma- separated quoted strings.

// the array to be quoted
$array = array('foo', 'bar', 'baz');

// the native PDO way:
// "Warning:  PDO::quote() expects parameter 1 to be string, array given"
$pdo = new PDO(...);
$cond = 'IN (' . $pdo->quote($array) . ')';

// the ExtendedPdo way:
// "IN ('foo', 'bar', 'baz')"
$pdo = new ExtendedPdo(...);
$cond = 'IN (' . $pdo->quote($array) . ')';

1.5.1.3. The perform() Method

The ExtendedPdo::perform() method will prepare a query with bound values in a single step. Also, because the native PDO does not deal with bound array values, perform() modifies the query string to expand the array-bound placeholder into multiple placeholders.

// the array to be quoted
$array = array('foo', 'bar', 'baz');

// the statement to prepare
$stm = 'SELECT * FROM test WHERE foo IN (:foo)'

// the native PDO way does not work (PHP Notice:  Array to string conversion)
$pdo = new ExtendedPdo(...);
$sth = $pdo->prepare($stm);
$sth->bindValue('foo', $array);

// the ExtendedPdo way allows a single call to prepare and execute the query.
// it quotes the array and expands the array placeholder directly in the
// query string.
$pdo = new ExtendedPdo(...);
$bind_values = array('foo' => $array);
$sth = $pdo->perform($stm, $bind_values);
echo $sth->queryString;
// the query string has been modified by ExtendedPdo to become
// "SELECT * FROM test WHERE foo IN (:foo_1, :foo_2, :foo_3)"

Finally, note that array quoting works only via the perform() method, not on returned PDOStatement instances.