Once the content’s structure is declared on our API, logical links between Students and Knowledge Nodes are created. We could call that « subscriptions ». But it goes further than that since this link is also the container of all the results, data computations and analysis for the student. A Student is related to all the Knowledge Nodes.\\

{{ :api1:knowledge_structure:knowledge_node_students_v1.png?600 | Knowledge Node Student schema}}

===Object resources===
^ Property     ^ Type      ^ Description         ^
| instance_id | Integer | The instance the knowledge node student belongs to |
| knowledge_node_id | Integer | The knowledge node the knowledge node student belongs to |
| student_id | Integer | The student the knowledge node student belongs to |
| active | Boolean | It becomes false when the reviewing has been done to the end |
| history | String | Sequence of binary results for the student on the knowledge node |
| next_review_at | Timestamp | The next revision date computed by the engine |
| knowledge_node_uid | String | The related knowledge node unique id |

===Create (POST)===

^ Method | POST |
^ URL | /knowledge_node_students |

==Parameters (*Required parameters)==

^ Property     ^ Type      ^ Description         ^
| knowledge_node_id* | Integer | The knowledge node the knowledge node student belongs to |
| student_id* | Integer | The student the knowledge node student belongs to |

==Send the request (JSON input example)==

<code>
{
	knowledge_node_id : 1,
	student_id: 1
}
</code>


==Get the response (JSON output example)==

<code>
{
	id : 1,
	knowledge_node_id : 1,
	student_id : 1,
	instance_id : 1,
	state : 0,
	history : ‘’,
	next_review_at : null,
	current_review_interv : 0,
	created_at : 2014-09-17 09:21:03,
	updated_at : 2014-09-17 09:21:03
}
</code>

===Fetch (GET)===

^ Method | GET |
^ URL | /knowledge_node_students/{knowledge_node_student_id %%||%% uid} |

If no knowledge_node_student_id or uid is provided it will fetch all the Knowledge Node Students for your instance.

==Get the response (JSON output example)==

**With ID provided**\\

<code>
{
	id : 1,
	knowledge_node_id : 1,
	student_id : 1,
	history : ‘’,
	next_review_at : null,
	active : true,
	created_at : 2014-09-17 09:21:03,
	updated_at : 2014-09-17 09:21:03
}
</code>


**Without ID provided**\\
<code>
[
	{
		id : 1,
		knowledge_node_id : 1,
		student_id : 1,
		next_review_at : null,
		active: true,
		created_at : 2014-09-17 09:21:03,
		updated_at : 2014-09-17 09:21:03
	},
	{
		id : 2,
		knowledge_node_id : 2,
		student_id : 1,
		next_review_at : null,
		active: true,
		created_at : 2014-09-17 09:21:13,
		updated_at : 2014-09-17 09:21:13
	}
]
</code>

===Fetch Knowledge Node Students by Student (GET)===

You can get all Student’s Knowledge Nodes by a simple request:

^ Method | GET |
^ URL | /students/{student_id}/knowledge_node_students/ |