- $maximumValues = array();
- foreach ( $this->primaryKey as $column ) {
- $maximumValues[$column] = $this->db->addQuotes( $maxRow->$column );
+ $maximumValues = [];
+ foreach ( $this->primaryKey as $alias => $column ) {
+ $name = is_numeric( $alias ) ? $column : $alias;
+ $maximumValues[$column] = $this->db->addQuotes( $maxRow->{$name} );