Tasks query API, yay!

sql/migrations/patches/20191007000601-tasks/up.sql

@@ -0,0 +1,14 @@
+CREATE TABLE tasks (
+    id integer GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+    owner integer NOT NULL REFERENCES users(id),
+    name text NOT NULL,
+    notes text,
+    schedule task_schedule NOT NULL DEFAULT 'daily',
+    min_frequency integer,
+    max_frequency integer,
+    created_at timestamptz NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated_at timestamptz NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    CHECK(min_frequency IS NULL OR max_frequency IS NULL OR max_frequency > min_frequency)
+);
+
+CREATE TRIGGER set_tasks_updated BEFORE UPDATE ON tasks FOR EACH ROW EXECUTE PROCEDURE set_updated_timestamp();