#  Deep dives

This part focuses on advanced Jet features such as **custom HTTP**, **SQL** queries, **conditional visibilit**y, and **related fields** (e.g. single relation). Let's start with the latter:

{% content-ref url="part-2-intermediate/single-relations" %}
[single-relations](https://docs.jetadmin.io/getting-started/part-2-intermediate/single-relations)
{% endcontent-ref %}

{% content-ref url="part-2-intermediate/reading-data-from-sql-1" %}
[reading-data-from-sql-1](https://docs.jetadmin.io/getting-started/part-2-intermediate/reading-data-from-sql-1)
{% endcontent-ref %}

{% content-ref url="part-2-intermediate/perform-api-requests" %}
[perform-api-requests](https://docs.jetadmin.io/getting-started/part-2-intermediate/perform-api-requests)
{% endcontent-ref %}