# Join functions

| Function                                                                                                     | Description                                       |
| ------------------------------------------------------------------------------------------------------------ | ------------------------------------------------- |
| [$join\_parent\_rel](https://api-docs.rightsline.com/search/search-functions/join-functions/join_parent_rel) | Match query against related parent relationships. |
| [$join\_child\_rel](https://api-docs.rightsline.com/search/search-functions/join-functions/join_child_rel)   | Match query against related child relationships.  |
| [$join](https://api-docs.rightsline.com/search/search-functions/join-functions/join)                         | Join any query to another query.                  |