Add Column
Current Schema
CREATE TABLE proposal_sources (
proposal_id TEXT NOT NULL,
event_id TEXT NOT NULL,
PRIMARY KEY (proposal_id, event_id),
FOREIGN KEY (proposal_id) REFERENCES proposals(id) ON DELETE RESTRICT DEFERRABLE INITIALLY DEFERRED,
FOREIGN KEY (event_id) REFERENCES events(id) ON DELETE RESTRICT DEFERRABLE INITIALLY DEFERRED
)