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Comment by RedCrowbar | Hacker News Reader

EdgeQL lets you do arbitrary joins as well. Here's how you could compute salaries of employees by department even if you for some reason don't have a link between Employee and Department:

    SELECT Department {
        name,
        employees := (
            SELECT Employee { name, salary } 
            FILTER Employee.department_name = Department.name
        )
    }

Links in EdgeQL are merely an abstraction over the fact that most joins in a well-normalized schema are done over primary keys.

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How do I join tables 1:1 without creating a subfield, i.e.:

table1: id, name

table2: table1_id, level

Desired result:

{id, name, level}

The most direct implementation of what you want would be:

  SELECT (Table1.id, Table1.name, Table2.level, Table2.table1_id)
  FILTER Table1.id = Table2.table1_id;

(This has a somewhat annoying extra output of table1_id, which could be projected away if necessary.)

If you want to use edgeql's shapes but still keep the essential join flavor, then something like:

  SELECT (Table1 { id, name }, Table2 { level })
  FILTER Table1.id = Table2.table1_id;

To make it a little more concrete, you can try this on the tutorial database (https://www.edgedb.com/tutorial)

  SELECT (Photo {uri}, User {name, email})
  FILTER Photo.author.id = User.id;

The tutorial database uses links, and so instead of having an author_id we have author.id, but having an author_id property would work just fine---except that then you'd have to do all the joins manually.

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