DATE_ADD (add an interval to a date, as MySQL writes it)

Syntax

DATE_ADD(<date-or-timestamp>, <interval>)

π id, DATE_ADD(started_on, INTERVAL 1 MONTH) → first_bill (Subscriptions)

Description

DATE_ADD is MySQL's way to write d + INTERVAL …. It adds an interval to a date or a timestamp, and a date stays a date.

Technical Description

DATE_ADD(d: DATE | TIMESTAMP, interval: DURATION) → the type of d. The interval is any DURATION, such as INTERVAL 1 MONTH, INTERVAL '2 weeks' or DURATION 'P1M'. Its months are added first, and a month from the 31st lands on a shorter month's last day. Its exact part is added after them. A DATE moved by part of a day is refused, because the result would be a TIMESTAMP: write CAST(d AS TIMESTAMP) + INTERVAL … for that. A TIMESTAMP is read at UTC. A NULL argument returns NULL. PURE, DETERMINISTIC.

Examples

The first bill, a month after the start:

π id, DATE_ADD(started_on, INTERVAL 1 MONTH) → first_bill (Subscriptions)

PROJECT id, DATE_ADD(started_on, INTERVAL 1 MONTH) -> first_bill (Subscriptions)

Pushdown

Runs in the engine.

See Also

date_sub, dateadd, duration-literal