How to Add a Column in PostgreSQL
Last updated July 24, 2026 · By the SaturnSQL team
Use ALTER TABLE ... ADD COLUMN. Since Postgres 11, adding a column with a constant DEFAULT is instant and does not rewrite the table, so it is safe on large tables.
ALTER TABLE orders ADD COLUMN discount NUMERIC(5,2) DEFAULT 0;Multiple columns, only if missing
ALTER TABLE orders
ADD COLUMN IF NOT EXISTS status TEXT,
ADD COLUMN IF NOT EXISTS updated_at TIMESTAMPTZ;A volatile default (e.g. now() at add-time is fine, but random() or a subquery) forces a full table rewrite; add the column first, then backfill in batches.
Run this in SaturnSQL
SaturnSQL is a browser-based SQL editor for teams: shared query library, schema-aware autocomplete, and scheduled exports to Google Sheets and Slack.
Try it free