ST_Cast

ST_Cast takes a geometry column and a string and returns a geometry column. The result column contains the input geometries cast to the geometry type specified by the string value. The string value can be 'point', 'multipoint', 'linestring', 'polygon', or 'geometry'. The function will return null when the input geometries cannot be cast to the specified type.

This function is commonly used to:

Cast from a specific geometry type to the generic geometry type when merging two geometry columns with different types.
Cast from the generic geometry type to a specific geometry type when using a function or tool that requires a specific geometry type as input.

Function	Syntax
Python	`cast(geometry, geometry_type)`
SQL	`ST_Cast(geometry, geometry_type)`

For more details, go to the GeoAnalytics Engine API reference for cast.

Examples

Python

SQL

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from geoanalytics.sql import functions as ST, Point

df = spark.createDataFrame([(Point(10, 10),)], ["point"])

df.printSchema()

df.select(ST.cast("point", "geometry").alias("point")).printSchema()

Result
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root
 |-- point: point (nullable = true)

root
 |-- point: geometry (nullable = true)

Version table

Release	Notes
1.0.0	Function introduced

ST_Cast

Examples

Version table

Related topics