Range Functions and Operators
Range Operators
- = - Description: Equals - Example: - openGauss=# SELECT int4range(1,5) = '[1,4]'::int4range AS RESULT; result -------- t (1 row)
- <> - Description: Does not equal to - Example: - openGauss=# SELECT numrange(1.1,2.2) <> numrange(1.1,2.3) AS RESULT; result -------- t (1 row)
- < - Description: Is less than - Example: - openGauss=# SELECT int4range(1,10) < int4range(2,3) AS RESULT; result -------- t (1 row)
- > - Description: Is greater than - Example: - openGauss=# SELECT int4range(1,10) > int4range(1,5) AS RESULT; result -------- t (1 row)
- <= - Description: Is less than or equals - Example: - openGauss=# SELECT numrange(1.1,2.2) <= numrange(1.1,2.2) AS RESULT; result -------- t (1 row)
- >= - Description: Is greater than or equals - Example: - openGauss=# SELECT numrange(1.1,2.2) >= numrange(1.1,2.0) AS RESULT; result -------- t (1 row)
- @> - Description: Contains ranges - Example: - openGauss=# SELECT int4range(2,4) @> int4range(2,3) AS RESULT; result -------- t (1 row)
- @> - Description: Contains elements - Example: - openGauss=# SELECT '[2011-01-01,2011-03-01)'::tsrange @> '2011-01-10'::timestamp AS RESULT; result -------- t (1 row)
- <@ - Description: Range is contained by - Example: - openGauss=# SELECT int4range(2,4) <@ int4range(1,7) AS RESULT; result -------- t (1 row)
- <@ - Description: Element is contained by - Example: - openGauss=# SELECT 42 <@ int4range(1,7) AS RESULT; result -------- f (1 row)
- && - Description: Overlap (have points in common) - Example: - openGauss=# SELECT int8range(3,7) && int8range(4,12) AS RESULT; result -------- t (1 row)
- « - Description: Strictly left of - Example: - openGauss=# SELECT int8range(1,10) << int8range(100,110) AS RESULT; result -------- t (1 row)
- >> - Description: Strictly right of - Example: - openGauss=# SELECT int8range(50,60) >> int8range(20,30) AS RESULT; result -------- t (1 row)
- &< - Description: Does not extend to the right of - Example: - openGauss=# SELECT int8range(1,20) &< int8range(18,20) AS RESULT; result -------- t (1 row)
- &> - Description: Does not extend to the left of - Example: - openGauss=# SELECT int8range(7,20) &> int8range(5,10) AS RESULT; result -------- t (1 row)
- -|- - Description: Is adjacent to - Example: - openGauss=# SELECT numrange(1.1,2.2) -|- numrange(2.2,3.3) AS RESULT; result -------- t (1 row)
Description: Union
Example:
```
openGauss=# SELECT numrange(5,15) + numrange(10,20) AS RESULT;
 result 
--------
 [5,20)
(1 row)
```
- * - Description: Intersection - Example: - openGauss=# SELECT int8range(5,15) * int8range(10,20) AS RESULT; result --------- [10,15) (1 row)
Description: Difference
Example:
```
openGauss=# SELECT int8range(5,15) - int8range(10,20) AS RESULT;
 result 
--------
 [5,10)
(1 row)
```
The simple comparison operators <, >, <=, and >= compare the lower bounds first, and only if those are equal, compare the upper bounds.
The «, >>, and -|- 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.
Range Functions
- numrange(numeric, numeric, [text]) - Description: Specifies a range. - Return type: Range's element type - Example: - openGauss=# SELECT numrange(1.1,2.2) AS RESULT; result -------- [1.1,2.2) (1 row) openGauss=# SELECT numrange(1.1,2.2, '()') AS RESULT; result -------- (1.1,2.2) (1 row)
- lower(anyrange) - Description: Lower bound of a range - Return type: Range's element type - Example: - openGauss=# SELECT lower(numrange(1.1,2.2)) AS RESULT; result -------- 1.1 (1 row)
- upper(anyrange) - Description: Upper bound of a range - Return type: Range's element type - Example: - openGauss=# SELECT upper(numrange(1.1,2.2)) AS RESULT; result -------- 2.2 (1 row)
- isempty(anyrange) - Description: Is the range empty? - Return type: Boolean - Example: - openGauss=# SELECT isempty(numrange(1.1,2.2)) AS RESULT; result -------- f (1 row)
- lower_inc(anyrange) - Description: Is the lower bound inclusive? - Return type: Boolean - Example: - openGauss=# SELECT lower_inc(numrange(1.1,2.2)) AS RESULT; result -------- t (1 row)
- upper_inc(anyrange) - Description: Is the upper bound inclusive? - Return type: Boolean - Example: - openGauss=# SELECT upper_inc(numrange(1.1,2.2)) AS RESULT; result -------- f (1 row)
- lower_inf(anyrange) - Description: Is the lower bound infinite? - Return type: Boolean - Example: - openGauss=# SELECT lower_inf('(,)'::daterange) AS RESULT; result -------- t (1 row)
- upper_inf(anyrange) - Description: Is the upper bound infinite? - Return type: Boolean - Example: - openGauss=# SELECT upper_inf('(,)'::daterange) AS RESULT; result -------- t (1 row)- The lower and upper functions return null if the range is empty or the requested bound is infinite. The lower_inc, upper_inc, lower_inf, and upper_inf functions all return false for an empty range. 
- elem_contained_by_range(anyelement, anyrange) - Description: Determines whether an element is within the range. - Return type: Boolean - Example: - openGauss=# SELECT elem_contained_by_range('2', numrange(1.1,2.2)); elem_contained_by_range ------------------------- t (1 row)