The INTERVAL data type stores a value that represents a span of time.
Aliases
There are no aliases for the interval type. However, CockroachDB supports using uninterpreted string literals in contexts where an INTERVAL value is otherwise expected.
Syntax
A constant value of type INTERVAL can be expressed using an
interpreted literal, or a
string literal
annotated with
type INTERVAL or
coerced to type
INTERVAL.
INTERVAL constants can be expressed using the following formats:
| Format | Description |
|---|---|
| SQL Standard | INTERVAL 'Y-M D H:M:S'Y-M D: Using a single value defines days only; using two values defines years and months. Values must be integers.H:M:S: Using a single value defines seconds only; using two values defines hours and minutes. Values can be integers or floats.Note that each side is optional. |
| ISO 8601 | INTERVAL 'P1Y2M3DT4H5M6S' |
| Traditional PostgreSQL | INTERVAL '1 year 2 months 3 days 4 hours 5 minutes 6 seconds' |
| Abbreviated PostgreSQL | INTERVAL '1 yr 2 mons 3 d 4 hrs 5 mins 6 secs' |
CockroachDB also supports using uninterpreted
string literals in contexts
where an INTERVAL value is otherwise expected.
Size
An INTERVAL column supports values up to 24 bytes in width, but the total storage size is likely to be larger due to CockroachDB metadata. Intervals are stored internally as months, days, and microseconds.
Precision
New in v19.1: Intervals are stored with microsecond precision instead of nanoseconds, and it is no longer possible to create intervals with nanosecond precision. As a result, parsing from a string or converting from a float or decimal will round to the nearest microsecond, as will any arithmetic operation (add, sub, mul, div) on intervals. CockroachDB rounds (instead of truncating) to match the behavior of Postgres.
When upgrading to 19.1, existing intervals with nanoseconds will no longer be able to return their nanosecond part. An existing table t with nanoseconds in intervals of column s can round them to the nearest microsecond with UPDATE t SET s = s + '0s'. Note that this could cause uniqueness problems if the interval is being used as a primary key.
Example
> CREATE TABLE intervals (a INT PRIMARY KEY, b INTERVAL);
> SHOW COLUMNS FROM intervals;
column_name | data_type | is_nullable | column_default | generation_expression | indices | is_hidden
-------------+-----------+-------------+----------------+-----------------------+-----------+-----------
a | INT8 | f | | | {primary} | f
b | INTERVAL | t | | | {} | f
(2 rows)
> INSERT INTO
intervals
VALUES (1, INTERVAL '1 year 2 months 3 days 4 hours 5 minutes 6 seconds'),
(2, INTERVAL '1-2 3 4:5:6'),
(3, '1-2 3 4:5:6');
> SELECT * FROM intervals;
a | b
---+-------------------------------
1 | 1 year 2 mons 3 days 04:05:06
2 | 1 year 2 mons 3 days 04:05:06
3 | 1 year 2 mons 3 days 04:05:06
(3 rows)
Supported casting and conversion
INTERVAL values can be cast to any of the following data types:
| Type | Details |
|---|---|
INT |
Converts to number of seconds (second precision) |
DECIMAL |
Converts to number of seconds (microsecond precision) |
FLOAT |
Converts to number of seconds (microsecond precision) |
STRING |
Converts to h-m-s format (microsecond precision) |
TIME |
Converts to HH:MM:SS.SSSSSS, the time equivalent to the interval after midnight (microsecond precision) |
See also
Was this helpful?
