Help Center/ GaussDB(DWS)/ More Documents/ SQL Syntax Reference (Kuala Lumpur Region)/ Functions and Operators/ Geometric Functions and Operators

Updated on 2022-08-16 GMT+08:00

View PDF

Geometric Functions and Operators

Geometric Operators

Description: Translation

For example:

SELECT box '((0,0),(1,1))' + point '(2.0,0)' AS RESULT;
   result    
-------------
 (3,1),(2,0)
(1 row)

Description: Translation

For example:

SELECT box '((0,0),(1,1))' - point '(2.0,0)' AS RESULT;
    result     
---------------
 (-1,1),(-2,0)
(1 row)

Description: Scaling out/rotation

For example:

SELECT box '((0,0),(1,1))' * point '(2.0,0)' AS RESULT;
   result    
-------------
 (2,2),(0,0)
(1 row)

Description: Scaling in/rotation

For example:

SELECT box '((0,0),(2,2))' / point '(2.0,0)' AS RESULT;
   result    
-------------
 (1,1),(0,0)
(1 row)

Description: Point or box of intersection

For example:

SELECT box'((1,-1),(-1,1))' # box'((1,1),(-1,-1))' AS RESULT;
 result 
--------
(1,1),(-1,-1)
(1 row)

Description: Number of paths or polygon vertexs

For example:

SELECT # path'((1,0),(0,1),(-1,0))' AS RESULT;
 result 
--------
      3
(1 row)

@-@

Description: Length or circumference

For example:

SELECT @-@ path '((0,0),(1,0))' AS RESULT;
 result 
--------
      2
(1 row)

Description: Center of box

For example:

SELECT @@ circle '((0,0),10)' AS RESULT;
 result 
--------
 (0,0)
(1 row)

Description: Closest point to first figure on second figure.

For example:

SELECT point '(0,0)' ## box '((2,0),(0,2))' AS RESULT;
 result 
--------
 (0,0)
(1 row)

<->

Description: Distance between the two figures.

For example:

SELECT circle '((0,0),1)' <-> circle '((5,0),1)' AS RESULT;
 result 
--------
      3
(1 row)

Description: Overlaps? (One point in common makes this true.)

For example:

SELECT box '((0,0),(1,1))' && box '((0,0),(2,2))' AS RESULT;
 result 
--------
 t
(1 row)

Description: Is strictly left of (no common horizontal coordinate)?

For example:

SELECT circle '((0,0),1)' << circle '((5,0),1)' AS RESULT;
 result 
--------
 t
(1 row)

Description: Is strictly right of (no common horizontal coordinate)?

For example:

SELECT circle '((5,0),1)' >> circle '((0,0),1)' AS RESULT;
 result 
--------
 t
(1 row)

Description: Does not extend to the right of?

For example:

SELECT box '((0,0),(1,1))' &< box '((0,0),(2,2))' AS RESULT;
 result 
--------
 t
(1 row)

Description: Does not extend to the left of?

For example:

SELECT box '((0,0),(3,3))' &> box '((0,0),(2,2))' AS RESULT;
 result 
--------
 t
(1 row)

<<|

Description: Is strictly below (no common horizontal coordinate)?

For example:

SELECT box '((0,0),(3,3))' <<| box '((3,4),(5,5))' AS RESULT;
 result 
--------
 t
(1 row)

|>>

Description: Is strictly above (no common horizontal coordinate)?

For example:

SELECT box '((3,4),(5,5))' |>> box '((0,0),(3,3))' AS RESULT;
 result 
--------
 t
(1 row)

&<|

Description: Does not extend above?

For example:

SELECT box '((0,0),(1,1))' &<| box '((0,0),(2,2))' AS RESULT;
 result 
--------
 t
(1 row)

|&>

Description: Does not extend below?

For example:

SELECT box '((0,0),(3,3))' |&> box '((0,0),(2,2))' AS RESULT;
 result 
--------
 t
(1 row)

Description: Is below (allows touching)?

For example:

SELECT box '((0,0),(-3,-3))' <^ box '((0,0),(2,2))' AS RESULT;
 result 
--------
 t
(1 row)

Description: Is above (allows touching)?

For example:

SELECT box '((0,0),(2,2))' >^ box '((0,0),(-3,-3))'  AS RESULT;
 result 
--------
 t
(1 row)

Description: Intersect?

For example:

SELECT lseg '((-1,0),(1,0))' ?# box '((-2,-2),(2,2))' AS RESULT;
 result 
--------
 t
(1 row)

Description: Is horizontal?

For example:

SELECT ?- lseg '((-1,0),(1,0))' AS RESULT;
 result 
--------
 t
(1 row)

Description: Are horizontally aligned?

For example:

SELECT point '(1,0)' ?- point '(0,0)' AS RESULT;
 result 
--------
 t
(1 row)

Description: Is vertical?

For example:

SELECT ?| lseg '((-1,0),(1,0))' AS RESULT;
 result 
--------
 f
(1 row)

Description: Are vertically aligned?

For example:

SELECT point '(0,1)' ?| point '(0,0)' AS RESULT;
 result 
--------
 t
(1 row)

?-|

Description: Are perpendicular?

For example:

SELECT lseg '((0,0),(0,1))' ?-| lseg '((0,0),(1,0))' AS RESULT;
 result 
--------
 t
(1 row)

?||

Description: Are parallel?

For example:

SELECT lseg '((-1,0),(1,0))' ?|| lseg '((-1,2),(1,2))' AS RESULT;
 result 
--------
 t
(1 row)

Description: Contains?

For example:

SELECT circle '((0,0),2)' @> point '(1,1)' AS RESULT;
 result 
--------
 t
(1 row)

Description: Contained in or on?

For example:

SELECT point '(1,1)' <@ circle '((0,0),2)' AS RESULT;
 result 
--------
 t
(1 row)

Description: Same as?

For example:

SELECT polygon '((0,0),(1,1))' ~= polygon '((1,1),(0,0))' AS RESULT;
 result 
--------
 t
(1 row)

Geometric Functions

area(object)

Description: Area calculation

Return type: double precision

For example:

SELECT area(box '((0,0),(1,1))') AS RESULT;
 result 
--------
      1
(1 row)

center(object)

Description: Figure center calculation

Return type: point

For example:

SELECT center(box '((0,0),(1,2))') AS RESULT;
 result  
---------
 (0.5,1)
(1 row)

diameter(circle)

Description: Circle diameter calculation

Return type: double precision

For example:

SELECT diameter(circle '((0,0),2.0)') AS RESULT;
 result 
--------
      4
(1 row)

height(box)

Description: Vertical size of box

Return type: double precision

For example:

SELECT height(box '((0,0),(1,1))') AS RESULT;
 result 
--------
      1
(1 row)

isclosed(path)

Description: A closed path?

Return type: boolean

For example:

SELECT isclosed(path '((0,0),(1,1),(2,0))') AS RESULT;
 result 
--------
 t
(1 row)

isopen(path)

Description: An open path?

Return type: boolean

For example:

SELECT isopen(path '[(0,0),(1,1),(2,0)]') AS RESULT;
 result 
--------
 t
(1 row)

length(object)

Description: Length calculation

Return type: double precision

For example:

SELECT length(path '((-1,0),(1,0))') AS RESULT;
 result 
--------
      4
(1 row)

npoints(path)

Description: Number of points in path

Return type: int

For example:

SELECT npoints(path '[(0,0),(1,1),(2,0)]') AS RESULT;
 result 
--------
      3
(1 row)

npoints(polygon)

Description: Number of points in polygon

Return type: int

For example:

SELECT npoints(polygon '((1,1),(0,0))') AS RESULT;
 result 
--------
      2
(1 row)

pclose(path)

Description: Converts path to closed.

Return type: path

For example:

SELECT pclose(path '[(0,0),(1,1),(2,0)]') AS RESULT;
       result        
---------------------
 ((0,0),(1,1),(2,0))
(1 row)

popen(path)

Description: Converts path to open.

Return type: path

For example:

SELECT popen(path '((0,0),(1,1),(2,0))') AS RESULT;
       result        
---------------------
 [(0,0),(1,1),(2,0)]
(1 row)

radius(circle)

Description: Circle diameter calculation

Return type: double precision

For example:

SELECT radius(circle '((0,0),2.0)') AS RESULT;
 result 
--------
      2
(1 row)

width(box)

Description: Horizontal size of box

Return type: double precision

For example:

SELECT width(box '((0,0),(1,1))') AS RESULT;
 result 
--------
      1
(1 row)

Geometric Type Conversion Functions

box(circle)

Description: Circle to box

Return type: box

For example:

SELECT box(circle '((0,0),2.0)') AS RESULT;
                                  result                                   
---------------------------------------------------------------------------
 (1.41421356237309,1.41421356237309),(-1.41421356237309,-1.41421356237309)
(1 row)

box(point, point)

Description: Points to box

Return type: box

For example:

SELECT box(point '(0,0)', point '(1,1)') AS RESULT;
   result    
-------------
 (1,1),(0,0)
(1 row)

box(polygon)

Description: Polygon to box

Return type: box

For example:

SELECT box(polygon '((0,0),(1,1),(2,0))') AS RESULT;
   result    
-------------
 (2,1),(0,0)
(1 row)

circle(box)

Description: Box to circle

Return type: circle

For example:

SELECT circle(box '((0,0),(1,1))') AS RESULT;
            result             
-------------------------------
 <(0.5,0.5),0.707106781186548>
(1 row)

circle(point, double precision)

Description: Center and radius to circle

Return type: circle

For example:

SELECT circle(point '(0,0)', 2.0) AS RESULT;
  result   
-----------
 <(0,0),2>
(1 row)

circle(polygon)

Description: Polygon to circle

Return type: circle

For example:

SELECT circle(polygon '((0,0),(1,1),(2,0))') AS RESULT;
                  result                   
-------------------------------------------
 <(1,0.333333333333333),0.924950591148529>
(1 row)

lseg(box)

Description: Box diagonal to line segment

Return type: lseg

For example:

SELECT lseg(box '((-1,0),(1,0))') AS RESULT;
     result     
----------------
 [(1,0),(-1,0)]
(1 row)

lseg(point, point)

Description: Points to line segment

Return type: lseg

For example:

SELECT lseg(point '(-1,0)', point '(1,0)') AS RESULT;
     result     
----------------
 [(-1,0),(1,0)]
(1 row)

path(polygon)

Description: Polygon to path

Return type: path

For example:

SELECT path(polygon '((0,0),(1,1),(2,0))') AS RESULT;
       result        
---------------------
 ((0,0),(1,1),(2,0))
(1 row)

point(double precision, double precision)

Description: Points

Return type: point

For example:

SELECT point(23.4, -44.5) AS RESULT;
    result    
--------------
 (23.4,-44.5)
(1 row)

point(box)

Description: Center of box

Return type: point

For example:

SELECT point(box '((-1,0),(1,0))') AS RESULT;
 result 
--------
 (0,0)
(1 row)

point(circle)

Description: Center of circle

Return type: point

For example:

SELECT point(circle '((0,0),2.0)') AS RESULT;
 result 
--------
 (0,0)
(1 row)

point(lseg)

Description: Center of line segment

Return type: point

For example:

SELECT point(lseg '((-1,0),(1,0))') AS RESULT;
 result 
--------
 (0,0)
(1 row)

point(polygon)

Description: Center of polygon

Return type: point

For example:

SELECT point(polygon '((0,0),(1,1),(2,0))') AS RESULT;
        result         
-----------------------
 (1,0.333333333333333)
(1 row)

polygon(box)

Description: Box to 4-point polygon

Return type: polygon

For example:

SELECT polygon(box '((0,0),(1,1))') AS RESULT;
          result           
---------------------------
 ((0,0),(0,1),(1,1),(1,0))
(1 row)

polygon(circle)

Description: Circle to 12-point polygon

Return type: polygon

For example:

SELECT polygon(circle '((0,0),2.0)') AS RESULT;
                                                                                                                                                result                                                                                      

-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 ((-2,0),(-1.73205080756888,1),(-1,1.73205080756888),(-1.22464679914735e-16,2),(1,1.73205080756888),(1.73205080756888,1),(2,2.44929359829471e-16),(1.73205080756888,-0.999999999999999),(1,-1.73205080756888),(3.67394039744206e-16,-2),(-0.999999999999999,-1.73205080756888),(-1.73205080756888,-1))
(1 row)

polygon(npts, circle)

Description: Circle to npts-point polygon

Return type: polygon

For example:

SELECT polygon(12, circle '((0,0),2.0)') AS RESULT;
                                                                                                                                                result                                                                                      

-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 ((-2,0),(-1.73205080756888,1),(-1,1.73205080756888),(-1.22464679914735e-16,2),(1,1.73205080756888),(1.73205080756888,1),(2,2.44929359829471e-16),(1.73205080756888,-0.999999999999999),(1,-1.73205080756888),(3.67394039744206e-16,-2),(-0.999999999999999,-1.73205080756888),(-1.73205080756888,-1))
(1 row)

polygon(path)

Description: Path to polygon

Return type: polygon

For example:

SELECT polygon(path '((0,0),(1,1),(2,0))') AS RESULT;
       result        
---------------------
 ((0,0),(1,1),(2,0))
(1 row)

Parent topic: Functions and Operators

Previous topic: Type Conversion Functions

Next topic: Network Address Functions and Operators

Feedback

Was this page helpful?

Helpful Not helpful

Provide feedback

Thank you very much for your feedback. We will continue working to improve the documentation.See the reply and handling status in My Cloud VOC.

The system is busy. Please try again later.

Which of the following issues have you encountered?

Content is inconsistent with the product UI

Unclear descriptions

Lack of examples or code

Incorrect steps

Can't find what I need

Lack of best practices

Feedback (optional)

0/500

Select at least one type of issue, and enter your comments or suggestions.

Enter a maximum of 500 characters.

Submit Cancel

For any further questions, feel free to contact us through the chatbot.

Chatbot