Accessor functions can be used to obtain values of the BIGINT, DOUBLE, or GEOMETRY type from different strings.

  • ST_XMax: returns the maximum X coordinate of g1.
  • ST_YMax: returns the maximum Y coordinate of g1.
  • ST_XMin: returns the minimum X coordinate of g1.
  • ST_YMin: returns the minimum Y coordinate of g1.
  • ST_Distance: returns the linear distance between g1 and g2.
  • ST_Distance_Sphere: returns the spherical distance between g1 and g2. You can specify the sphere radius. The default radius is 6,370,986 meters.
  • ST_Area: returns the Euclidean area of g1 in 2D space.
  • ST_Centroid: returns the geometric center of g1.
  • ST_ConvexHull: returns the convex hull of g1. The convex hull is the smallest convex geometry that encloses all geometries in g1.
  • ST_CoordDim: returns the dimension of coordinate components of g1.
  • ST_Dimension: returns the inherent dimension of g1. The inherent dimension must be less than or equal to the coordinate dimension.
  • ST_IsClosed: returns 1 if the start and end points of a linestring or multilinestring coincide. A value of 1 indicates true, and a value of 0 indicates false.
  • ST_IsEmpty: returns 0 if g1 is an empty geometry collection, polygon, or point. A value of 0 indicates true, and a value of 1 indicates false.
  • ST_IsValid: returns 1 if g1 is valid. A value of 1 indicates true.
  • Geometry_invalid_reason: returns the reason why g1 is invalid.
  • ST_Length: returns the Euclidean length for a linestring or multilinestring, or the great-circle distance for a geography.
  • Line_locate_point: returns a float that represents the location of the closest point on the specified linestring to the specified point as a fraction of total line length.
  • Line_interpolate_point: returns a point along a line at a fractional distance from the start of the line.
  • Line_interpolate_points: returns all points along a line at a fractional distance from the start of the line.
  • ST_NumInteriorRing: returns the number of interior rings in a polygon geometry.
  • ST_InteriorRings: returns a geometry array of all interior rings found within the specified geometry, or an empty array if the polygon has no interior rings. If the specified geometry is empty, null is returned. If the specified geometry is not a polygon, an error is returned.
  • ST_NumGeometries: returns the number of geometries within the collection. If the geometry is a collection of geometries, such as a GEOMETRYCOLLECTION or MULTI* object, the number of geometries is returned. 1 is returned for each geometry. 0 is returned for empty geometries. An empty geometry in a GEOMETRYCOLLECTION object counts as one geometry.
  • ST_GeometryN: returns the GEOMETRY element at a specified integer index. Indexes start from 1. If the specified geometry is a collection of geometries, such as a GEOMETRYCOLLECTION or MULTI* object, the geometry at the specified index is returned. If the specified index is less than 1 or greater than the total number of elements in the collection, null is returned.
  • ST_PointN: returns the vertex of the specified linestring at the specified integer index. Indexes start from 1. If the specified index is less than 1 or greater than the total number of elements in the collection, null is returned.
  • ST_Geometries: returns an array of geometries within the specified collection. If the specified geometry is not a multi-geometry, a one-element array is returned. If the specified geometry is empty, null is returned.
  • ST_InteriorRingN: returns the interior ring element at the specified index. Indexes start from 1. If the specified index is less than 1 or greater than the total number of interior rings in the specified geometry, null is returned. If the specified geometry is not a polygon, an error is returned.
  • ST_NumPoints: returns the number of points within a geometry.
  • ST_IsRing: returns 1 if and only if a linestring is closed and simple. A value of 1 indicates true, and a value of 0 indicates false.
  • ST_StartPoint: returns the first point of a line geometry as a point.
  • Simplify_geometry: uses the Ramer-Douglas-Peucker algorithm to return a simplified version of the specified geometry in the GEOMETRY data type. This function ensures that created derived geometries (in particular, polygons) are valid.
  • ST_EndPoint: returns the last point of a line geometry as a point.
  • ST_Points: returns an array of points from the specified linestring geometry object.
  • ST_X: returns the X coordinate of a point.
  • ST_Y: returns the Y coordinate of a point.
  • ST_GeometryType: returns the type of a geometry in the VARCHAR data type.

ST_XMax

ST_XMax(g1)
  • Description: This function returns the maximum X coordinate of g1.
  • Data type of the return value: DOUBLE.
  • Example: 
    SELECT ST_XMax(ST_GeomFromText('POINT (1.5 2.5)'));
    Returned results:
    +----------------------------------------------+
| ST_XMax(ST_GeomFromText('POINT (1.5 2.5)'))  |
+----------------------------------------------+
|                         1.5                  |

ST_YMax 

ST_YMax(g1)
  • Description: This function returns the maximum Y coordinate of g1.
  • Data type of the return value: DOUBLE.
  • Example: 
    SELECT ST_YMax(ST_GeomFromText('POINT (1.5 2.5)'));
    Returned results:
    +----------------------------------------------+
| ST_YMax(ST_GeomFromText('POINT (1.5 2.5)'))  |
+----------------------------------------------+
|                         2.5                  |

ST_XMin 

ST_XMin(g1)
  • Description: This function returns the minimum X coordinate of g1.
  • Data type of the return value: DOUBLE.
  • Example: 
    SELECT ST_XMin(ST_GeomFromText('MULTIPOINT (1 2, 2 4, 3 6, 4 8)'));
    Returned results:
    +-------------------------------------------------------------+
| ST_XMin(ST_GeomFromText('MULTIPOINT (1 2, 2 4, 3 6, 4 8)')) |
+-------------------------------------------------------------+
|                         1.0                                 |

ST_YMin 

ST_YMin(g1)
  • Description: This function returns the minimum Y coordinate of g1.
  • Data type of the return value: DOUBLE.
  • Example: 
    SELECT ST_YMin(ST_GeomFromText('MULTIPOINT (1 2, 2 4, 3 6, 4 8)'));
    Returned results:
    +-------------------------------------------------------------+
| ST_YMin(ST_GeomFromText('MULTIPOINT (1 2, 2 4, 3 6, 4 8)')) |
+-------------------------------------------------------------+
|                        2.0                                  |

ST_Distance 

ST_Distance(g1, g2)
  • Description: This function returns the linear distance between g1 and g2.
  • Data type of the return value: DOUBLE.
  • Example: 
    SELECT ST_Distance(ST_Point(1,1), ST_Point(2,2));
    Returned results:
    +-------------------------------------------+
| ST_Distance(ST_Point(1,1), ST_Point(2,2)) |
+-------------------------------------------+
|                        1.4142135623730951 |

ST_Distance_Sphere 

ST_Distance_Sphere(g1, g2 [, radius])
  • Description: This function returns the spherical distance between g1 and g2. You can specify the sphere radius. The default radius is 6,370,986 meters.
  • Data type of the return value: DOUBLE.
  • Example: 
    SELECT ST_Distance_Sphere(point(1,1), point(2,2));
    Returned results:
    +--------------------------------------------+
| ST_Distance_Sphere(point(1,1), point(2,2)) |
+--------------------------------------------+
|                         157225.08654191086 |

ST_Area 

ST_Area(g1)
  • Description: This function returns the Euclidean area of g1 in 2D space.
  • Data type of the return value: DOUBLE.
  • Example: 
    SELECT ST_Area(ST_GeometryFromText('POLYGON ((2 2, 2 6, 6 6, 6 2))'));
    Returned results:
    +------------------------------------------------------------------------+
| ST_Area(ST_GeometryFromText('POLYGON ((2 2, 2 6, 6 6, 6 2))'))         |
+------------------------------------------------------------------------+
|                        16.0                                            |

ST_Centroid

ST_Centroid(g1)
  • Description: This function returns the geometric center of g1.
  • Data type of the return value: GEOMETRY. If you execute the SELECT statement to query results of this function, the returned results are corrupted. You can call the ST_AsText function to convert the results to readable text.
  • Example: 
    SELECT ST_AsText(ST_Centroid(ST_GeometryFromText('POINT (3 5)')));
    Returned results:
    +-------------------------------------------------------------------+
| ST_AsText(ST_Centroid(ST_GeometryFromText('POINT (3 5)')))        |
+-------------------------------------------------------------------+
|                       POINT (3 5)                                 |

ST_ConvexHull

ST_ConvexHull(g1)
  • Description: This function returns the convex hull of g1. The convex hull is the smallest convex geometry that encloses all geometries in g1.
  • Data type of the return value: GEOMETRY. If you execute the SELECT statement to query results of this function, the returned results are corrupted. You can call the ST_AsText function to convert the results to readable text.
  • Example: 
    SELECT ST_AsText(ST_ConvexHull(ST_GeometryFromText('LINESTRING (20 20, 30 30)')));
    Returned results:
    +--------------------------------------------------------------------------------+
| ST_AsText(ST_ConvexHull(ST_GeometryFromText('LINESTRING (20 20, 30 30)')))     |
+--------------------------------------------------------------------------------+
|               POLYGON ((1 1, 5 1, 6 6, 1 1))                                   |

ST_CoordDim

ST_CoordDim(g1)
  • Description: This function returns the dimension of coordinate components of g1.
  • Data type of the return value: TINYINT.
  • Example: 
    SELECT ST_CoordDim(ST_GeometryFromText('POLYGON ((1 1, 1 4, 4 4, 4 1))'));
    Returned results:
    +--------------------------------------------------------------------------------+
| ST_CoordDim(ST_GeometryFromText('POLYGON ((1 1, 1 4, 4 4, 4 1))'))             |
+--------------------------------------------------------------------------------+ 
|             2                                                                  |

ST_Dimension

ST_Dimension(g1)
  • Description: This function returns the inherent dimension of g1. The inherent dimension must be less than or equal to the coordinate dimension.
  • Data type of the return value: TINYINT.
  • Example: 
    SELECT ST_Dimension(ST_GeometryFromText('POLYGON ((1 1, 1 4, 4 4, 4 1))'));
    Returned results:
    +--------------------------------------------------------------------------------+
| ST_Dimension(ST_GeometryFromText('POLYGON ((1 1, 1 4, 4 4, 4 1))'))            |
+--------------------------------------------------------------------------------+ 
|             2                                                                  |

ST_IsClosed

ST_IsClosed(g1)
  • Description: This function returns 1 if the start and end points of a linestring or multilinestring coincide. A value of 1 indicates true, and a value of 0 indicates false.
  • Data type of the return value: INT.
  • Example: 
    SELECT ST_IsClosed(ST_GeometryFromText('LINESTRING (1 1, 2 2, 1 3, 1 1)'));
    Returned results:
    +-------------------------------------------------------------------------------+
| ST_IsClosed(ST_GeometryFromText('LINESTRING (1 1, 2 2, 1 3, 1 1)'))           |
+-------------------------------------------------------------------------------+   
|               1                                                               |

ST_IsEmpty

ST_IsEmpty(g1)
  • Description: This function returns 0 if g1 is an empty geometry collection, polygon, or point. A value of 0 indicates true, and a value of 1 indicates false.
  • Data type of the return value: INT.
  • Example: 
    SELECT ST_IsEmpty(ST_GeometryFromText('POINT (1.5 2.5)'));
    Returned results:
    +-------------------------------------------------------------+
| ST_IsEmpty(ST_GeometryFromText('POINT (1.5 2.5)'))          |
+-------------------------------------------------------------+   
|              0                                              |

ST_IsValid

ST_IsValid(g1)
  • Description: This function returns 1 if g1 is valid. A value of 1 indicates true.
  • Data type of the return value: INT.
  • Example: 
    SELECT ST_IsValid(ST_GeometryFromText('LINESTRING (1 1, 2 2, 1 3, 1 1)'));
    Returned results:
    +------------------------------------------------------------------------+
| ST_IsValid(ST_GeometryFromText('LINESTRING (1 1, 2 2, 1 3, 1 1)'))     |
+-------------------------------------------------------------------- ---+   
|                      1                                                 |

Geometry_invalid_reason

Geometry_invalid_reason(g1)
  • Description: This function returns the reason why g1 is invalid.
  • Data type of the return value: VARCHAR.
  • Example: 
    SELECT Geometry_invalid_reason(ST_GeometryFromText('POLYGON ((0 0, 1 1, 0 1, 1 0, 0 0))'));
    Returned results:
    +----------------------------------------------------------------------------------------+
| Geometry_invalid_reason(ST_GeometryFromText('POLYGON ((0 0, 1 1, 0 1, 1 0, 0 0))'))    |
+----------------------------------------------------------------------------------------+   
|     Intersecting or overlapping segments at or near (1.0 0.0) and (1.0 1.0)            |

ST_Length

ST_Length(g1)
  • Description: This function returns the Euclidean length for a linestring or multilinestring, or the great-circle distance for a geography.
  • Data type of the return value: DOUBLE.
  • Example: 
    SELECT ST_Length(ST_GeometryFromText('LINESTRING (1 1, 1 2)'));
    Returned results:
    +----------------------------------------------------------+
| ST_Length(ST_GeometryFromText('LINESTRING (1 1, 1 2)'))  |
+----------------------------------------------------------+   
|          1.0                                             |

Line_locate_point

Line_locate_point(g1, g2)
  • Description: This function returns a float that represents the location of the closest point on the specified linestring to the specified point as a fraction of total line length.
  • Data type of the return value: DOUBLE.
  • Example: 
    SELECT Line_locate_point(ST_GeometryFromText('LINESTRING (0 0, 0 1)'), ST_Point(0, 0.2));
    Returned results:
    +-------------------------------------------------------------------------------------+
| Line_locate_point(ST_GeometryFromText('LINESTRING (0 0, 0 1)'), ST_Point(0, 0.2))   |
+-------------------------------------------------------------------------------------+   
|                                         0.2                                         |

Line_interpolate_point

Line_interpolate_point(g1, d)
  • Description: This function returns a point along a line at a fractional distance from the start of the line.
  • Data type of the return value: GEOMETRY. If you execute the SELECT statement to query results of this function, the returned results are corrupted. You can call the ST_AsText function to convert the results to readable text.
  • Example: 
    SELECT ST_AsText(Line_interpolate_point(ST_GeometryFromText('LINESTRING (0 0, 2 2)'), 0.5));
    Returned results:
    +----------------------------------------------------------------------------------------+
| ST_AsText(Line_interpolate_point(ST_GeometryFromText('LINESTRING (0 0, 2 2)'), 0.5))   |
+----------------------------------------------------------------------------------------+   
|                                        POINT (1 1)                                     |

Line_interpolate_points

Line_interpolate_points(g1, d)
  • Description: This function returns all points along a line at a fractional distance from the start of the line.
  • Data type of the return value: GEOMETRY. If you execute the SELECT statement to query results of this function, the returned results are corrupted. You can call the transform function to apply Lambda expressions to each array element.
  • Example: 
    SELECT transform(Line_interpolate_points(ST_GeometryFromText('LINESTRING (0 0, 1 1, 10 10)'), 0.4), x -> ST_AsText(x));
    Returned results:
    +-----------------------------------------------------------------------------------------------------------------+
| transform(Line_interpolate_points(ST_GeometryFromText('LINESTRING (0 0, 1 1, 10 10)'), 0.4), x -> ST_AsText(x)) |
+-----------------------------------------------------------------------------------------------------------------+   
|      ["POINT (4.000000000000001 4.000000000000001)","POINT (8 8)"]                                               |

ST_NumInteriorRing

ST_NumInteriorRing(g1)
  • Description: This function returns the number of interior rings in a polygon geometry.
  • Data type of the return value: BIGINT.
  • Example: 
    SELECT ST_NumInteriorRing(ST_GeometryFromText('POLYGON ((0 0, 0 5, 5 5, 5 0, 0 0))'));
    Returned results:
    +-------------------------------------------------------------------------------------+
| ST_NumInteriorRing(ST_GeometryFromText('POLYGON ((0 0, 0 5, 5 5, 5 0, 0 0))'))      |
+-------------------------------------------------------------------------------------+   
|                                      0                                              |

ST_InteriorRings

ST_InteriorRings(g1)
  • Description: This function returns a geometry array of all interior rings found within the specified geometry, or an empty array if the polygon has no interior rings. If the specified geometry is empty, null is returned. If the specified geometry is not a polygon, an error is returned.
  • Data type of the return value: Array[GEOMETRY[GEOMETRY].
  • Example: 
    SELECT ST_InteriorRings(ST_GeometryFromText('POLYGON EMPTY'));
    Returned results:
    +----------------------------------------------------------------------+
| ST_InteriorRings(ST_GeometryFromText('POLYGON EMPTY'))               |
+----------------------------------------------------------------------+   
|                                    null                              |

ST_NumGeometries

ST_NumGeometries(g1)
  • Description: This function returns the number of geometries within the collection. If the geometry is a collection of geometries, such as a GEOMETRYCOLLECTION or MULTI* object, the number of geometries is returned. 1 is returned for each geometry. 0 is returned for empty geometries. An empty geometry in a GEOMETRYCOLLECTION object counts as one geometry.
  • Data type of the return value: INT.
  • Example: 
    SELECT ST_NumGeometries(ST_GeometryFromText('POINT (1 2)'));
    Returned results:
    +----------------------------------------------------------------------+
| ST_NumGeometries(ST_GeometryFromText('POINT (1 2)'))                 |
+----------------------------------------------------------------------+   
|                                    1                                 |

ST_GeometryN

ST_GeometryN(g, i)
  • Description: This function returns the GEOMETRY element at a specified integer index. Indexes start from 1. If the specified geometry is a collection of geometries, such as a GEOMETRYCOLLECTION or MULTI* object, the geometry at the specified index is returned. If the specified index is less than 1 or greater than the total number of elements in the collection, null is returned.
  • Data type of the return value: GEOMETRY. If you execute the SELECT statement to query results of this function, the returned results are corrupted. You can call the ST_AsText function to convert the results to readable text.
  • Example: 
    SELECT ST_ASText(ST_GeometryN(ST_GeometryFromText('POINT (1 2)'), 1));
    Returned results:
    +---------------------------------------------------------------------------------+
|   ST_ASText(ST_GeometryN(ST_GeometryFromText('POINT (1 2)'), 1))                |
+---------------------------------------------------------------------------------+   
|                  POINT (1 2)                                                    |

ST_PointN

ST_PointN(g, i)
  • Description: This function returns the vertex of the specified linestring at the specified integer index. Indexes start from 1. If the specified index is less than 1 or greater than the total number of elements in the collection, null is returned.
  • Data type of the return value: GEOMETRY. If you execute the SELECT statement to query results of this function, the returned results are corrupted. You can call the ST_AsText function to convert the results to readable text.
  • Example: 
    SELECT ST_ASText(ST_PointN(ST_GeometryFromText('LINESTRING(1 2, 3 4, 5 6, 7 8)'), 3));
    Returned results:
    +---------------------------------------------------------------------------------------+
|   ST_ASText(ST_PointN(ST_GeometryFromText('LINESTRING(1 2, 3 4, 5 6, 7 8)'), 3))      |
+---------------------------------------------------------------------------------------+   
|                  POINT (5 6)                                                          |

ST_Geometries

ST_Geometries(g)
  • Description: This function returns an array of geometries within the specified collection. If the specified geometry is not a multi-geometry, a one-element array is returned. If the specified geometry is empty, null is returned.
  • Data type of the return value: GEOMETRY. If you execute the SELECT statement to query results of this function, the returned results are corrupted. You can call the transform function to apply Lambda expressions to each array element.
  • Example: 
    SELECT transform(ST_Geometries(ST_GeometryFromText('POINT (1 5)')), x -> ST_ASText(x));
    Returned results:
    +---------------------------------------------------------------------------------------+
|   transform(ST_Geometries(ST_GeometryFromText('POINT (1 5)')), x -> ST_ASText(x))     |
+---------------------------------------------------------------------------------------+   
|                  POINT (1 5)                                                          |

ST_InteriorRingN

ST_InteriorRingN(g, d)
  • Description: This function returns the interior ring element at the specified index. Indexes start from 1. If the specified index is less than 1 or greater than the total number of interior rings in the specified geometry, null is returned. If the specified geometry is not a polygon, an error is returned.
  • Data type of the return value: GEOMETRY. If you execute the SELECT statement to query results of this function, the returned results are corrupted. You can call the ST_AsText function to convert the results to readable text.
  • Example: 
    SELECT ST_ASText(ST_InteriorRingN(ST_GeometryFromText('POLYGON ((0 0, 0 3, 3 3, 3 0, 0 0), (1 1, 1 2, 2 2, 2 1, 1 1))'), 1));
    Returned results:
    +-----------------------------------------------------------------------------------------------------------------------------+
|    ST_ASText(ST_InteriorRingN(ST_GeometryFromText('POLYGON ((0 0, 0 3, 3 3, 3 0, 0 0), (1 1, 1 2, 2 2, 2 1, 1 1))'), 1))    |
+-----------------------------------------------------------------------------------------------------------------------------+   
|                 LINESTRING (1 1, 1 2, 2 2, 2 1, 1 1)                                                                        |

ST_NumPoints

 ST_NumPoints(g)
  • Description: This function returns the number of points within a geometry in the BIGINT data type.
  • Data type of the return value: BIGINT.
  • Example: 
    SELECT  ST_NumPoints(ST_GeometryFromText('POINT (1 2)'));
    Returned results:
    +-------------------------------------------------------------------------+
|     ST_NumPoints(ST_GeometryFromText('POINT (1 2)'))                    |
+-------------------------------------------------------------------------+   
|                 1                                                       |

ST_IsRing

ST_IsRing(g)
  • Description: This function returns 1 if and only if the line type is closed and simple. A value of 1 indicates true, and a value of 0 indicates false.
  • Data type of the return value: INT.
  • Example: 
    SELECT  ST_IsRing(ST_GeometryFromText('LINESTRING (1 1, 1 3, 2 3, 2 1, 1 1)'));
    Returned results:
    +---------------------------------------------------------------------------------+
|     ST_IsRing(ST_GeometryFromText('LINESTRING (1 1, 1 3, 2 3, 2 1, 1 1)'))      |
+---------------------------------------------------------------------------------+   
|                 1                                                               |

ST_StartPoint

ST_StartPoint(g)
  • Description: This function returns the first point of a line geometry as a point.
  • Data type of the return value: GEOMETRY. If you execute the SELECT statement to query results of this function, the returned results are corrupted. You can call the ST_AsText function to convert the results to readable text.
  • Example: 
    SELECT  ST_AsText(ST_StartPoint(ST_GeometryFromText('LINESTRING (8 4, 4 8, 5 6)')));
    Returned results:
    +-------------------------------------------------------------------------------------+
|     ST_AsText(ST_StartPoint(ST_GeometryFromText('LINESTRING (8 4, 4 8, 5 6)')))     |
+-------------------------------------------------------------------------------------+   
|                 POINT (8 4)                                                         |

Simplify_geometry

Simplify_geometry(g, d)
  • Description: This function uses the Ramer-Douglas-Peucker algorithm to return a simplified version of the specified geometry in the GEOMETRY data type. This function ensures that created derived geometries (in particular, polygons) are valid.
  • Data type of the return value: GEOMETRY. If you execute the SELECT statement to query results of this function, the returned results are corrupted. You can call the ST_AsText function to convert the results to readable text.
  • Example: 
    SELECT  ST_AsText(Simplify_geometry(ST_GeometryFromText('POLYGON ((1 0, 2 1, 3 1, 3 1, 4 1, 1 0))'), 1.5));
    Returned results:
    +-----------------------------------------------------------------------------------------------------------+
|     ST_AsText(Simplify_geometry(ST_GeometryFromText('POLYGON ((1 0, 2 1, 3 1, 3 1, 4 1, 1 0))'), 1.5))    |
+-----------------------------------------------------------------------------------------------------------+   
|                  POLYGON ((1 0, 4 1, 2 1, 1 0)))                                                          |

ST_EndPoint

ST_EndPoint(g)
  • Description: This function returns the last point of a line geometry as a point.
  • Data type of the return value: GEOMETRY. If you execute the SELECT statement to query results of this function, the returned results are corrupted. You can call the ST_AsText function to convert the results to readable text.
  • Example: 
    SELECT ST_AsText(ST_EndPoint(ST_GeometryFromText('LINESTRING (8 4, 4 8, 5 6)')));
    Returned results:
    +-----------------------------------------------------------------------------------+
| ST_AsText(ST_EndPoint(ST_GeometryFromText('LINESTRING (8 4, 4 8, 5 6)')))         |
+-----------------------------------------------------------------------------------+   
|                  POINT (5 6)                                                      |

ST_Points

ST_Points(g)
  • Description: This function returns an array of points from the specified linestring geometry object.
  • Data type of the return value: GEOMETRY. If you execute the SELECT statement to query results of this function, the returned results are corrupted. You can call the transform function to apply Lambda expressions to each array element.
  • Example: 
    SELECT transform(ST_Points(ST_GeometryFromText('POINT (0 0)')), x -> ST_AsText(x));
    Returned results:
    +-----------------------------------------------------------------------------------+
| transform(ST_Points(ST_GeometryFromText('POINT (0 0)')), x -> ST_AsText(x))       |
+-----------------------------------------------------------------------------------+   
|                  ["POINT (0 0)"]                                                  |

ST_X

ST_X(g)
  • Description: This function returns the X coordinate of a point.
  • Data type of the return value: DOUBLE.
  • Example: 
    SELECT ST_X(ST_GeometryFromText('POINT (1 2)'));
    Returned results:
    +------------------------------------------------+
|ST_X(ST_GeometryFromText('POINT (1 2)'))        |
+------------------------------------------------+   
|                1.0                             |

ST_Y

ST_Y(g)
  • Description: This function returns the Y coordinate of a point.
  • Data type of the return value: DOUBLE.
  • Example: 
    SELECT ST_Y(ST_GeometryFromText('POINT (1 2)'));
    Returned results:
    +------------------------------------------------+
|ST_Y(ST_GeometryFromText('POINT (1 2)'))        |
+------------------------------------------------+   
|                2.0                             |

ST_GeometryType

ST_GeometryType(g1)
  • Description: This function returns the type of a geometry.
  • Data type of the return value: VARCHAR.
  • Example: 
    SELECT ST_GeometryType(ST_Point(1, 4))
    Returned results:
    +---------------------------------------+
|ST_GeometryType(ST_Point(1, 4))        |
+---------------------------------------+   
|                 ST_Point              |