ConditionAggregate.php

<?php

namespace Drupal\Core\Entity\Query\Sql;

use Drupal\Core\Database\Query\SelectInterface;
use Drupal\Core\Entity\Query\ConditionAggregateBase;
use Drupal\Core\Entity\Query\ConditionAggregateInterface;
use Drupal\Core\Database\Query\Condition as SqlCondition;
use Drupal\Core\Entity\Query\QueryBase;

/**
 * Defines the aggregate condition for sql based storage.
 */
class ConditionAggregate extends ConditionAggregateBase {
    
    /**
     * {@inheritdoc}
     */
    public function compile($conditionContainer) {
        // If this is not the top level condition group then the sql query is
        // added to the $conditionContainer object by this function itself. The
        // SQL query object is only necessary to pass to Query::addField() so it
        // can join tables as necessary. On the other hand, conditions need to be
        // added to the $conditionContainer object to keep grouping.
        $sql_query = $conditionContainer instanceof SelectInterface ? $conditionContainer : $conditionContainer->sqlQuery;
        $tables = new Tables($sql_query);
        foreach ($this->conditions as $condition) {
            if ($condition['field'] instanceof ConditionAggregateInterface) {
                $sql_condition = new SqlCondition($condition['field']->getConjunction());
                // Add the SQL query to the object before calling this method again.
                $sql_condition->sqlQuery = $sql_query;
                $condition['field']->compile($sql_condition);
                $sql_query->condition($sql_condition);
            }
            else {
                $type = strtoupper($this->conjunction) == 'OR' || $condition['operator'] == 'IS NULL' ? 'LEFT' : 'INNER';
                $field = $tables->addField($condition['field'], $type, $condition['langcode']);
                $condition_class = QueryBase::getClass($this->namespaces, 'Condition');
                $condition_class::translateCondition($condition, $sql_query, $tables->isFieldCaseSensitive($condition['field']));
                $function = $condition['function'];
                $placeholder = ':db_placeholder_' . $conditionContainer->nextPlaceholder();
                $conditionContainer->having("{$function}({$field}) {$condition['operator']} {$placeholder}", [
                    $placeholder => $condition['value'],
                ]);
            }
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function exists($field, $function, $langcode = NULL) {
        return $this->condition($field, $function, NULL, 'IS NOT NULL', $langcode);
    }
    
    /**
     * {@inheritdoc}
     */
    public function notExists($field, $function, $langcode = NULL) {
        return $this->condition($field, $function, NULL, 'IS NULL', $langcode);
    }

}