relational

minimalistic DRY database layer for PHP, with adapters for PostgreSQL and MySQL and lightweight ORM

Yet another database abstraction layer ?

Yes, but this one is based on a minimalistic approach, its concise and has just as little as possible overhead.

Why not PDO ?

PDO is unnecessarily complex and has design flaws.

PDO, using prepared statement(*):

$db = new PDO($dsn,$username,$password);
$statement = $db->prepare('SELECT * FROM users WHERE id=:id');
$statement->execute( [ ':id' => $id ] );
while($row = $statement->fetch(PDO::FETCH_ASSOC)) {
    echo $row['id'] . ' ' . $row['name'];
}

PDO, plain (passing parameters directly in sql string, user must care about escaping):

$db = new PDO($dsn,$username,$password);
$rs = $db->query('SELECT * FROM users WHERE id='.$db->quote($id));
foreach( $rs as $row ) {
    echo $row['id'] . ' ' . $row['name'];
}

relational:

$db = reDBFactory::connect($config_string);
foreach( $db->queryAssoc('SELECT * FROM users WHERE id=?',array($id)) as $row ) {
    echo $row['id'] . ' ' . $row['name'];
}

Please note that parameter passing, query execution and fetching result rows is combined in a single call to queryAssoc().

That's it. Concise.

Besides queryAssoc() there are additional query methods for casual purposes: queryArray(), queryOneArray(), queryOneAssoc(), exec(), queryOneValue(), queryOneColumn(), queryKeyValueArray(), as well as methods for transaction control: begin(), commit(), rollback().

(*) Why not PDO, really ?

PDO has a design flaw: to use its parameter binding interface it requires using "prepared statements". The PDO creators encourage developers to use prepared statements everywhere. That contradicts the purpose of prepared statements. PDO abuses them for parameter binding in lack of a sober parameter binding interface for non-prepared statements.

The problems with prepared statements:

• statement preparation takes extra time,
• prepared statements will allocate ressources in database,
• the execution plan the database query planner decides for a statement can be suboptimal: it did not have chance to consider actual data at time of preparation.

Prepared statements should be used with care, in selected situations only, not like a hammer.

Safe Parameter Binding !

"relational" provides an easy to use parameter binding interface for PHP (without requiring prepared statements as in PDO).

It intentionelly does NOT provide functions for escaping data for use in SQL (as e.g. mysqli_real_escape_string()). There is no need for it, all parameters must be passed through the parameter binding interface.

Why no "fetch row" methods ? Doesn't it consume huge amounts of memory when always fetching whole result at once ?

No! Actually the mysqli and pgsql interface libraries (by default) do fetch the whole result anyway, whenever user requests to fetch the first row.

So it really does not matter. Fetching results row-by-row in PHP is just unnecessary overhead.