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9.20. Range Functions and Operators

See Section 8.17 for an overview of range types.

Table 9.53 shows the specialized operators available for range types. In addition to those, the usual comparison operators shown in Table 9.1 are available for range types. The comparison operators order first by the range lower bounds, and only if those are equal do they compare the upper bounds. This does not usually result in a useful overall ordering, but the operators are provided to allow unique indexes to be constructed on ranges.

Table 9.53. Range Operators

Operator

Description

Example(s)

anyrange @> anyrangeboolean

Does the first range contain the second?

int4range(2,4) @> int4range(2,3)t

anyrange @> anyelementboolean

Does the range contain the element?

'[2011-01-01,2011-03-01)'::tsrange @> '2011-01-10'::timestampt

anyrange <@ anyrangeboolean

Is the first range contained by the second?

int4range(2,4) <@ int4range(1,7)t

anyelement <@ anyrangeboolean

Is the element contained in the range?

42 <@ int4range(1,7)f

anyrange && anyrangeboolean

Do the ranges overlap, that is, have any elements in common?

int8range(3,7) && int8range(4,12)t

anyrange << anyrangeboolean

Is the first range strictly left of the second?

int8range(1,10) << int8range(100,110)t

anyrange >> anyrangeboolean

Is the first range strictly right of the second?

int8range(50,60) >> int8range(20,30)t

anyrange &< anyrangeboolean

Does the first range not extend to the right of the second?

int8range(1,20) &< int8range(18,20)t

anyrange &> anyrangeboolean

Does the first range not extend to the left of the second?

int8range(7,20) &> int8range(5,10)t

anyrange -|- anyrangeboolean

Are the ranges adjacent?

numrange(1.1,2.2) -|- numrange(2.2,3.3)t

anyrange + anyrangeanyrange

Computes the union of the ranges. The ranges must overlap or be adjacent, so that the union is a single range (but see range_merge()).

numrange(5,15) + numrange(10,20)[5,20)

anyrange * anyrangeanyrange

Computes the intersection of the ranges.

int8range(5,15) * int8range(10,20)[10,15)

anyrange - anyrangeanyrange

Computes the difference of the ranges. The second range must not be contained in the first in such a way that the difference would not be a single range.

int8range(5,15) - int8range(10,20)[5,10)


The left-of/right-of/adjacent operators always return false when an empty range is involved; that is, an empty range is not considered to be either before or after any other range.

Table 9.54 shows the functions available for use with range types.

Table 9.54. Range Functions

Function

Description

Example(s)

lower ( anyrange ) → anyelement

Extracts the lower bound of the range (NULL if the range is empty or the lower bound is infinite).

lower(numrange(1.1,2.2))1.1

upper ( anyrange ) → anyelement

Extracts the upper bound of the range (NULL if the range is empty or the upper bound is infinite).

upper(numrange(1.1,2.2))2.2

isempty ( anyrange ) → boolean

Is the range empty?

isempty(numrange(1.1,2.2))f

lower_inc ( anyrange ) → boolean

Is the range's lower bound inclusive?

lower_inc(numrange(1.1,2.2))t

upper_inc ( anyrange ) → boolean

Is the range's upper bound inclusive?

upper_inc(numrange(1.1,2.2))f

lower_inf ( anyrange ) → boolean

Is the range's lower bound infinite?

lower_inf('(,)'::daterange)t

upper_inf ( anyrange ) → boolean

Is the range's upper bound infinite?

upper_inf('(,)'::daterange)t

range_merge ( anyrange, anyrange ) → anyrange

Computes the smallest range that includes both of the given ranges.

range_merge('[1,2)'::int4range, '[3,4)'::int4range)[1,4)


The lower_inc, upper_inc, lower_inf, and upper_inf functions all return false for an empty range.