SeeSection 8.17for an overview of range types.
Table 9.50shows the operators available for range types.
Table 9.50. Range Operators
Operator
Description
Example
Result
=
equal
int4range(1,5) = '[1,4]'::int4range
t
<>
not equal
numrange(1.1,2.2) <> numrange(1.1,2.3)
t
<
less than
int4range(1,10) < int4range(2,3)
t
>
greater than
int4range(1,10) > int4range(1,5)
t
<=
less than or equal
numrange(1.1,2.2) <= numrange(1.1,2.2)
t
>=
greater than or equal
numrange(1.1,2.2) >= numrange(1.1,2.0)
t
@>
contains range
int4range(2,4) @> int4range(2,3)
t
@>
contains element
'[2011-01-01,2011-03-01)'::tsrange @> '2011-01-10'::timestamp
t
<@
range is contained by
int4range(2,4) <@ int4range(1,7)
t
<@
element is contained by
42 <@ int4range(1,7)
f
&&
overlap (have points in common)
int8range(3,7) && int8range(4,12)
t
<<
strictly left of
int8range(1,10) << int8range(100,110)
t
>>
strictly right of
int8range(50,60) >> int8range(20,30)
t
&<
does not extend to the right of
int8range(1,20) &< int8range(18,20)
t
&>
does not extend to the left of
int8range(7,20) &> int8range(5,10)
t
`-
-`
is adjacent to
`numrange(1.1,2.2) -
- numrange(2.2,3.3)`
t
+
union
numrange(5,15) + numrange(10,20)
[5,20)
*
intersection
int8range(5,15) * int8range(10,20)
[10,15)
-
difference
int8range(5,15) - int8range(10,20)
[5,10)
The simple comparison operators<,>,<=, and>=compare the lower bounds first, and only if those are equal, compare the upper bounds. These comparisons are not usually very useful for ranges, but are provided to allow B-tree indexes to be constructed on ranges.
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.
The union and difference operators will fail if the resulting range would need to contain two disjoint sub-ranges, as such a range cannot be represented.
Table 9.51shows the functions available for use with range types.
Table 9.51. Range Functions
Function
Return Type
Description
Example
Result
lower(anyrange)
range's element type
lower bound of range
lower(numrange(1.1,2.2))
1.1
upper(anyrange)
range's element type
upper bound of range
upper(numrange(1.1,2.2))
2.2
isempty(anyrange)
boolean
is the range empty?
isempty(numrange(1.1,2.2))
false
lower_inc(anyrange)
boolean
is the lower bound inclusive?
lower_inc(numrange(1.1,2.2))
true
upper_inc(anyrange)
boolean
is the upper bound inclusive?
upper_inc(numrange(1.1,2.2))
false
lower_inf(anyrange)
boolean
is the lower bound infinite?
lower_inf('(,)'::daterange)
true
upper_inf(anyrange)
boolean
is the upper bound infinite?
upper_inf('(,)'::daterange)
true
range_merge(anyrange,anyrange)
anyrange
the smallest range which includes both of the given ranges
range_merge('[1,2)'::int4range, '[3,4)'::int4range)
[1,4)
Thelowerandupperfunctions return null if the range is empty or the requested bound is infinite. Thelower_inc,upper_inc,lower_inf, andupper_inffunctions all return false for an empty range.