Objects

Subtopics

EdgeDB allows for various relationships to be established between objects by using links. Accessing links is very similar to accessing properties. However, an important thing to remember is that following links always results in a set of objects (without duplicates), unlike properties. For example, to query all the content on the watchlists of all the users try:

Input

Run

select Account.watchlist { title };

select Account.watchlist { title };

Output Objects

Press the 'Run' button to evaluate the input

In the example above, Account.watchlist links to the Content objects linked from each Account, and the Content type has a property called title that we chose to display.

Links in EdgeDB are directional, but they can be traversed in reverse direction and refer to the object at the start of a link by using the .< instead of .. We call this a backlink. When following a backlink it is best to specify the type of the object at the source using [is SomeType]. For example, to get all those users who have some Content on their watchlists try:

Input

Run

# [is Account] lets EdgeDB know select all the Account
# objects that link back via a link called watchlist.
# Knowing the concrete type, it can now access the 
# Account's username property
select Content.<watchlist[is Account] { username };

# [is Account] lets EdgeDB know select all the Account
# objects that link back via a link called watchlist.
# Knowing the concrete type, it can now access the 
# Account's username property
select Content.<watchlist[is Account] { username };

Output Objects

Press the 'Run' button to evaluate the input

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