Organization

This EMP/DEPT-style example stores each employee’s required department link and exposes its readonly inverse as Department.employees. It also includes an optional self-referencing manager link.

type Department {
  required unique code: str
  required name: str
  multi link employees: Employee inverse department
}

type Employee {
  required unique employee_no: str
  required name: str
  required title: str
  required salary: int64
  required active: bool
  required hired_at: datetime
  required link department: Department
  link manager: Employee
}

Create data

Apply the schema to a new database:

cargo run -p gelite-cli -- schema apply examples/organization.geli --database organization.db

Open gelite repl --database organization.db, then insert two departments:

insert Department { code := "INVESTIGATION", name := "Investigation" }

insert Department { code := "ARCHIVE", name := "Records Archive" }

Insert the manager first. Link assignments look up existing objects through their unique fields, so generated IDs do not need to be copied from earlier commands:

insert Employee {
  employee_no := "MG-667",
  name := "Sheri Tachibana",
  title := "Chief Investigator",
  salary := 92000,
  active := true,
  hired_at := "2026-04-01T09:00:00Z",
  department := (
    select Department { id }
    filter .code = "INVESTIGATION"
  )
}

insert Employee {
  employee_no := "MG-001",
  name := "Emma Sakuraba",
  title := "Investigator",
  salary := 68000,
  active := true,
  hired_at := "2026-04-15T09:00:00Z",
  department := (
    select Department { id }
    filter .code = "INVESTIGATION"
  ),
  manager := (
    select Employee { id }
    filter .employee_no = "MG-667"
  )
}

insert Employee {
  employee_no := "MG-002",
  name := "Hiro Nikaido",
  title := "Archivist",
  salary := 64000,
  active := true,
  hired_at := "2026-05-01T09:00:00Z",
  department := (
    select Department { id }
    filter .code = "ARCHIVE"
  ),
  manager := null
}

Department.employees is derived from the stored Employee.department link. No separate population or synchronization step is needed. Assignments to the inverse field are rejected; change the stored employee link instead.

Query a multi link

select Department {
  code,
  name,
  employees: {
    employee_no,
    name,
    title,
    manager: { name }
  }
}
order by .code asc

The REPL renders employees as a collection of nested objects. A department without linked employees receives []. Multi-link collection order is not defined by the language.

Filter through the inverse link

Select departments with at least one employee earning 90000 or more:

select Department { code, name, employees: { name, salary } }
filter .employees.salary >= 90000
order by .code asc

The filter selects departments; the returned employees collection still contains all employees in each selected department. Each multi-path comparison has its own existence scope. Two comparisons combined with and may be satisfied by different employees. Use an explicit scope when one employee must satisfy both conditions:

select Department { code, name, employees: { name, salary } }
filter exists .employees {
  .name = "Sheri Tachibana" and .salary >= 90000
}
order by .code asc

Inside the braces, paths refer to one employee. The returned collection still contains all employees in the selected department. not exists .employees { .salary >= 90000 } also selects departments with no employees, whereas an existence predicate with a negated body requires at least one employee.

Change the stored relationship

Move the archive employee to the investigation department:

update Employee
filter .employee_no = "MG-002"
set {
  department := (
    select Department { id }
    filter .code = "INVESTIGATION"
  )
}

select Department { code, employees: { employee_no, name } }
order by .code asc

The archive department now returns [], and the investigation department returns three employees. No inverse-side update is needed.

Query nested links

select Employee {
  employee_no,
  name,
  title,
  department: {
    code,
    name
  },
  manager: {
    name,
    title
  }
}
filter .active = true
  and .department.id in (
    select Department { id }
    filter .code in ["INVESTIGATION", "ARCHIVE"]
  )
  and .employee_no not in ["MG-999"]
order by .salary desc, .name asc
limit 10
offset 0

The nested select finds matching department identities in its own query scope. The employee-number condition keeps a literal-list membership example beside it.

Find top-level employees whose optional manager link is absent:

select Employee { employee_no, name, title }
filter .manager.id = null
order by .name asc

The REPL preserves the top-level field order and renders selected links as nested objects. A missing optional link is NULL:

employee_no\tname\ttitle\tdepartment\tmanager
MG-667\tSheri Tachibana\tChief Investigator\t{code: INVESTIGATION, name: Investigation}\tNULL