duration

duration(X)

X is a STRING scalar. It is composed of an integer and a unit of time (y, M, w, d, B, H, m, s, ms, us, ns). For examples: "2y", "3M", "30m", "100ms".

Convert X to DURATION type which indicates the length of a time interval.

Note:

• The unit of the time interval used for grouping cannot be more granular than the unit of the temporal column.

• Time units are case-sensitive, for example, "M" means month and "m" means minute. If the unit of the time interval is M, use function month to convert the time column values to months.

• Data of DURATION type cannot participate in calculations. For example, comparisons between DURATION values (such as duration(20ms) >= duration(10ms)) are not supported.

y=duration("20H")
y
// output
20H

typestr(y)
// output
DURATION

In function bar, we can use a number followed by a time unit to indicate a duration.

t=table(take(2018.01.01T01:00:00+1..10,10) join take(2018.01.01T02:00:00+1..10,10) join take(2018.01.01T08:00:00+1..10,10) as time, rand(1.0, 30) as x)
select max(x) from t group by bar(time, 5);

select max(x) from t group by bar(time, 1m);

Related information: Trading Calendar