silverstripe-postgresql/code/PostgreSQLQueryBuilder.php
2015-05-04 15:36:49 +01:00

43 lines
1.2 KiB
PHP

<?php
class PostgreSQLQueryBuilder extends DBQueryBuilder {
/**
* Return the LIMIT clause ready for inserting into a query.
*
* @param SQLSelect $query The expression object to build from
* @param array $parameters Out parameter for the resulting query parameters
* @return string The finalised limit SQL fragment
*/
public function buildLimitFragment(SQLSelect $query, array &$parameters) {
$nl = $this->getSeparator();
// Ensure limit is given
$limit = $query->getLimit();
if(empty($limit)) return '';
// For literal values return this as the limit SQL
if( ! is_array($limit)) {
return "{$nl}LIMIT $limit";
}
// Assert that the array version provides the 'limit' key
if( ! array_key_exists('limit', $limit) || ($limit['limit'] !== null && ! is_numeric($limit['limit']))) {
throw new InvalidArgumentException(
'DBQueryBuilder::buildLimitSQL(): Wrong format for $limit: '. var_export($limit, true)
);
}
if($limit['limit'] === null) {
$limit['limit'] = 'ALL';
}
$clause = "{$nl}LIMIT {$limit['limit']}";
if(isset($limit['start']) && is_numeric($limit['start']) && $limit['start'] !== 0) {
$clause .= " OFFSET {$limit['start']}";
}
return $clause;
}
}