Validates Postgres foreign key ON DELETE and ON UPDATE actions.

Examples

With this rule:

[where: [referenced_tables: ["accounts"]], on_delete: :restrict]

Before, the foreign key deletes orders when an account is deleted:

CREATE TABLE orders (
  id uuid PRIMARY KEY,
  account_id uuid NOT NULL REFERENCES accounts(id) ON DELETE CASCADE
);

That may silently remove business records that should survive account cleanup or require an explicit archival flow.

After, use the action required by the rule:

CREATE TABLE orders (
  id uuid PRIMARY KEY,
  account_id uuid NOT NULL REFERENCES accounts(id) ON DELETE RESTRICT
);

Postgres now blocks accidental parent deletion until the application handles dependent rows intentionally.

Notes

This check only validates actions you configure. If a rule only sets on_delete, the ON UPDATE action is ignored for that rule.

Options

• :validate - explicit false disables this check.
• :rules - rule keyword list or non-empty list of rule keyword lists.
• :on_delete - expected foreign key ON DELETE action inside each rule.
• :on_update - expected foreign key ON UPDATE action inside each rule.

This check requires at least one of :on_delete or :on_update, so bare-module configuration is not valid.

Run globally:

{Bylaw.Db.Adapters.Postgres.Checks.ForeignKeyActions,
 rules: [on_delete: :restrict, on_update: :restrict]}

Run only for matching rule scopes:

{Bylaw.Db.Adapters.Postgres.Checks.ForeignKeyActions,
 rules: [
   [
     where: [referenced_tables: ["lookup_statuses"]],
     on_delete: :restrict,
     on_update: :restrict
   ],
   [
     where: [tables: ["messages"]],
     except: [constraints: ["messages_status_id_fkey"]],
     on_delete: :cascade
   ]
 ]}

A foreign key can match more than one rule, and matching rules accumulate.

Usage

Add this module to the checks passed to Bylaw.Db.Adapters.Postgres.validate/2. See the README usage section for the full ExUnit setup.