Overview

WherobotsDB supports SQL/MM Part3 Spatial SQL Standard. It includes four kinds of SQL operators as follows. All these operators can be directly called through:

var myDataFrame = sedona.sql("YOUR_SQL")

Alternatively, expr and selectExpr can be used:

myDataFrame.withColumn("geometry", expr("ST_*")).selectExpr("ST_*")
  • Constructor: Construct a Geometry given an input string or coordinates
    • Example: ST_GeomFromWKT (string). Create a Geometry from a WKT String.
    • Documentation: Here
  • Function: Execute a function on the given column or columns
    • Example: ST_Distance (A, B). Given two Geometry A and B, return the Euclidean distance of A and B.
    • Documentation: Here
  • Aggregate function: Return the aggregated value on the given column
    • Example: ST_Envelope_Aggr (Geometry column). Given a Geometry column, calculate the entire envelope boundary of this column.
    • Documentation: Here
  • Predicate: Execute a logic judgement on the given columns and return true or false
    • Example: ST_Contains (A, B). Check if A fully contains B. Return "True" if yes, else return "False".
    • Documentation: Here
  • Nearest-Neighbor search: Identifying the k-nearest neighbors for a given spatial point or region based on geographic proximity
    • Example: ST_KNN(R: Table, S: Table, k: Integer, use_spheroid: Boolean). Join operation to find the k-nearest neighbors of a point or region in a spatial dataset.
    • Documentation: Here

WherobotsDB supports SparkSQL query optimizer, documentation is Here

Last update: July 31, 2024 20:33:00