xPDOExpression

xPDO\Om\xPDOExpression is an immutable value object that wraps a raw SQL fragment so xPDO can inline it verbatim instead of binding it as a parameter. Use it wherever xPDOQuery accepts a column value or a SELECT entry when you need a SQL expression — a function call (NOW(), CURRENT_TIMESTAMP), an arithmetic expression (counter + 1), or an aggregate with an alias (COUNT(*) AS total). Valid contexts include SET, SELECT, WHERE, HAVING, GROUP BY, and ORDER BY.

The expression is embedded without quoting, escaping, or parameterisation, so keeping it safe is the caller's responsibility.

[!WARNING] Never pass unsanitised user input to xPDOExpression or to xPDO::expression(). The string is inserted into the generated SQL as-is and can lead to SQL injection.

Creating an Expression¶

The class is final; build instances with the xPDO::expression() factory:

$expr = $xpdo->expression('NOW()');

Examples¶

Sort by a raw expression:

$query = $xpdo->newQuery('modResource');
$query->sortby($xpdo->expression('COUNT(*)'), 'DESC');

Use an expression as a bound value in WHERE:

$query = $xpdo->newQuery('modResource');
$query->where(array(
    'createdon:<=' => $xpdo->expression('NOW()'),
));

See Also¶

• xPDO.expression
• xPDOQuery
• xPDOQuery.sortby