BEGIN TRANSACTION

BEGIN starts an explicit transaction boundary.

After BEGIN, changes are pending until you COMMIT or ROLLBACK.

Core Concepts

flowchart TD
  A[BEGIN ...] --> B[Execute writes]
  B --> C{Finish path}
  C -->|COMMIT| D[Persist changes]
  C -->|ROLLBACK| E[Discard changes]

BEGIN form	Typical behavior
`BEGIN` / `BEGIN DEFERRED`	Acquire locks lazily when needed
`BEGIN IMMEDIATE`	Start reserved write intent earlier
`BEGIN EXCLUSIVE`	Stronger locking mode

BEGIN;
-- write statements
COMMIT;

Expected output
Transaction starts and ends explicitly around writes.

BEGIN IMMEDIATE;
-- write statements
COMMIT;

Expected output
Transaction starts with immediate write intent.

-- Setup table for BEGIN examples.
CREATE TABLE tx_begin_demo (
  id     INTEGER PRIMARY KEY,
  note   TEXT NOT NULL
);

Expected output
Demo table created.

-- Explicit transaction using BEGIN.
BEGIN TRANSACTION;

INSERT INTO tx_begin_demo (note)
VALUES ('step one'), ('step two');

COMMIT;

Expected output
Both inserts committed together.

-- Verify inserted rows.
SELECT id, note
FROM tx_begin_demo
ORDER BY id;

id	note
1	step one
2	step two

SQLite Nuance

BEGIN does not itself change data; it marks transaction start in the current connection.

Lock behavior differs slightly by begin mode (DEFERRED, IMMEDIATE, EXCLUSIVE).

Pitfall

Starting a transaction and forgetting to finalize it, leaving locks and pending work.

Best Practice

Always pair every BEGIN with a clear end path (COMMIT on success, ROLLBACK on failure).

Begin a transaction and insert one row into tx_begin_demo with note manual tx.

View Solution

BEGIN;

INSERT INTO tx_begin_demo (note)
VALUES ('manual tx');

COMMIT;

Expected output
New row inserted and persisted at commit time.