/**
* Query ::= 'SELECT' columns
* 'FROM' Source
* ['WHERE' Constraint]
* ['ORDER BY' orderings]
*
* @param QOM\QueryObjectModelInterface $query
*
* @return string
*/
public function convert(QOM\QueryObjectModelInterface $query)
{
$columns = $this->convertColumns($query->getColumns());
$source = $this->convertSource($query->getSource());
$constraint = '';
$orderings = '';
if ($query->getConstraint() !== null) {
$constraint = $this->convertConstraint($query->getConstraint());
}
if (count($query->getOrderings())) {
$orderings = $this->convertOrderings($query->getOrderings());
}
return $this->generator->evalQuery($source, $columns, $constraint, $orderings);
}
