protected Select::prepareCountQuery()
Prepares a count query from the current query object.
Return value
\Drupal\Core\Database\Query\Select A new query object ready to have COUNT(*) performed on it.
File
- core/lib/Drupal/Core/Database/Query/Select.php, line 718
Class
- Select
- Query builder for SELECT statements.
Namespace
Drupal\Core\Database\Query
Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 | protected function prepareCountQuery() { // Create our new query object that we will mutate into a count query. $count = clone($this); $group_by = $count->getGroupBy(); $having = $count->havingConditions(); if (!$count->distinct && !isset($having[0])) { // When not executing a distinct query, we can zero-out existing fields // and expressions that are not used by a GROUP BY or HAVING. Fields // listed in a GROUP BY or HAVING clause need to be present in the // query. $fields = &$count->getFields(); foreach (array_keys($fields) as $field) { if (empty($group_by[$field])) { unset($fields[$field]); } } $expressions = &$count->getExpressions(); foreach (array_keys($expressions) as $field) { if (empty($group_by[$field])) { unset($expressions[$field]); } } // Also remove 'all_fields' statements, which are expanded into tablename.* // when the query is executed. foreach ($count->tables as &$table) { unset($table['all_fields']); } } // If we've just removed all fields from the query, make sure there is at // least one so that the query still runs. $count->addExpression('1'); // Ordering a count query is a waste of cycles, and breaks on some // databases anyway. $orders = &$count->getOrderBy(); $orders = array(); if ($count->distinct && !empty($group_by)) { // If the query is distinct and contains a GROUP BY, we need to remove the // distinct because SQL99 does not support counting on distinct multiple fields. $count->distinct = FALSE; } // If there are any dependent queries to UNION, prepare each of those for // the count query also. foreach ($count->union as &$union) { $union['query'] = $union['query']->prepareCountQuery(); } return $count;} |
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