eZ\Publish\Core\Search\Legacy\Content\Common\Gateway\SortClauseHandler\Field::applyJoin PHP Method

    public function applyJoin(SelectQuery $query, SortClause $sortClause, $number, array $languageSettings)
    {
        /** @var \eZ\Publish\API\Repository\Values\Content\Query\SortClause\Target\FieldTarget $fieldTarget */
        $fieldTarget = $sortClause->targetData;
        $fieldMap = $this->contentTypeHandler->getSearchableFieldMap();
        if (!isset($fieldMap[$fieldTarget->typeIdentifier][$fieldTarget->fieldIdentifier]['field_definition_id'])) {
            throw new InvalidArgumentException('$sortClause->targetData', 'No searchable fields found for the given sort clause target ' . "'{$fieldTarget->fieldIdentifier}' on '{$fieldTarget->typeIdentifier}'.");
        }
        $fieldDefinitionId = $fieldMap[$fieldTarget->typeIdentifier][$fieldTarget->fieldIdentifier]['field_definition_id'];
        $table = $this->getSortTableName($number);
        $query->leftJoin($query->alias($this->dbHandler->quoteTable('ezcontentobject_attribute'), $this->dbHandler->quoteIdentifier($table)), $query->expr->lAnd($query->expr->eq($query->bindValue($fieldDefinitionId, null, PDO::PARAM_INT), $this->dbHandler->quoteColumn('contentclassattribute_id', $table)), $query->expr->eq($this->dbHandler->quoteColumn('contentobject_id', $table), $this->dbHandler->quoteColumn('id', 'ezcontentobject')), $query->expr->eq($this->dbHandler->quoteColumn('version', $table), $this->dbHandler->quoteColumn('current_version', 'ezcontentobject')), $this->getFieldCondition($query, $languageSettings, $table)));
    }