Constructor
ST_GeomFromWKT¶
Introduction: Construct a Geometry from Wkt
Format:
ST_GeomFromWKT (Wkt:string)
Since: v1.0.0
Spark SQL example:
SELECT ST_GeomFromWKT(polygontable._c0) AS polygonshape
FROM polygontable
SELECT ST_GeomFromWKT('POINT(40.7128 -74.0060)') AS geometry
ST_GeomFromWKB¶
Introduction: Construct a Geometry from WKB string
Format:
ST_GeomFromWKB (Wkb:string)
Since: v1.0.0
Spark SQL example:
SELECT ST_GeomFromWKB(polygontable._c0) AS polygonshape
FROM polygontable
ST_GeomFromGeoJSON¶
Introduction: Construct a Geometry from GeoJson
Format: ST_GeomFromGeoJSON (GeoJson:string)
Since: v1.0.0
Spark SQL example:
var polygonJsonDf = sparkSession.read.format("csv").option("delimiter","\t").option("header","false").load(geoJsonGeomInputLocation)
polygonJsonDf.createOrReplaceTempView("polygontable")
polygonJsonDf.show()
var polygonDf = sparkSession.sql(
"""
| SELECT ST_GeomFromGeoJSON(polygontable._c0) AS countyshape
| FROM polygontable
""".stripMargin)
polygonDf.show()
Warning
The way that SedonaSQL reads GeoJSON is different from that in SparkSQL
Read ESRI Shapefile¶
Introduction: Construct a DataFrame from a Shapefile
Since: v1.0.0
SparkSQL example:
var spatialRDD = new SpatialRDD[Geometry]
spatialRDD.rawSpatialRDD = ShapefileReader.readToGeometryRDD(sparkSession.sparkContext, shapefileInputLocation)
var rawSpatialDf = Adapter.toDf(spatialRDD,sparkSession)
rawSpatialDf.createOrReplaceTempView("rawSpatialDf")
var spatialDf = sparkSession.sql("""
| ST_GeomFromWKT(rddshape), _c1, _c2
| FROM rawSpatialDf
""".stripMargin)
spatialDf.show()
spatialDf.printSchema()
Note
The file extensions of .shp, .shx, .dbf must be in lowercase. Assume you have a shape file called myShapefile, the file structure should be like this:
- shapefile1
- shapefile2
- myshapefile
- myshapefile.shp
- myshapefile.shx
- myshapefile.dbf
- myshapefile...
- ...
Warning
Please make sure you use ST_GeomFromWKT to create Geometry type column otherwise that column cannot be used in SedonaSQL.
If the file you are reading contains non-ASCII characters you'll need to explicitly set the encoding
via sedona.global.charset system property before the call to ShapefileReader.readToGeometryRDD.
Example:
System.setProperty("sedona.global.charset", "utf8")
ST_Point¶
Introduction: Construct a Point from X and Y
Format: ST_Point (X:decimal, Y:decimal)
Format: ST_Point (X:decimal, Y:decimal, Z:decimal)
Since: v1.0.0
Spark SQL example:
SELECT ST_Point(CAST(pointtable._c0 AS Decimal(24,20)), CAST(pointtable._c1 AS Decimal(24,20))) AS pointshape
FROM pointtable
ST_PointFromText¶
Introduction: Construct a Point from Text, delimited by Delimiter
Format: ST_PointFromText (Text:string, Delimiter:char)
Since: v1.0.0
Spark SQL example:
SELECT ST_PointFromText(pointtable._c0,',') AS pointshape
FROM pointtable
SELECT ST_PointFromText('40.7128,-74.0060', ',') AS pointshape
ST_PolygonFromText¶
Introduction: Construct a Polygon from Text, delimited by Delimiter. Path must be closed
Format: ST_PolygonFromText (Text:string, Delimiter:char)
Since: v1.0.0
Spark SQL example:
SELECT ST_PolygonFromText(polygontable._c0,',') AS polygonshape
FROM polygontable
SELECT ST_PolygonFromText('-74.0428197,40.6867969,-74.0421975,40.6921336,-74.0508020,40.6912794,-74.0428197,40.6867969', ',') AS polygonshape
ST_LineStringFromText¶
Introduction: Construct a LineString from Text, delimited by Delimiter
Format: ST_LineStringFromText (Text:string, Delimiter:char)
Since: v1.0.0
Spark SQL example:
SELECT ST_LineStringFromText(linestringtable._c0,',') AS linestringshape
FROM linestringtable
SELECT ST_LineStringFromText('-74.0428197,40.6867969,-74.0421975,40.6921336,-74.0508020,40.6912794', ',') AS linestringshape
ST_PolygonFromEnvelope¶
Introduction: Construct a Polygon from MinX, MinY, MaxX, MaxY.
Format: ST_PolygonFromEnvelope (MinX:decimal, MinY:decimal, MaxX:decimal, MaxY:decimal)
Since: v1.0.0
Spark SQL example:
SELECT *
FROM pointdf
WHERE ST_Contains(ST_PolygonFromEnvelope(1.0,100.0,1000.0,1100.0), pointdf.pointshape)
ST_GeomFromGeoHash¶
Introduction: Create Geometry from geohash string and optional precision
Format: ST_GeomFromGeoHash(geohash: string, precision: int)
Since: v1.1.1
Spark SQL example:
SELECT ST_GeomFromGeoHash('s00twy01mt', 4) AS geom
result:
+--------------------------------------------------------------------------------------------------------------------+
|geom |
+--------------------------------------------------------------------------------------------------------------------+
|POLYGON ((0.703125 0.87890625, 0.703125 1.0546875, 1.0546875 1.0546875, 1.0546875 0.87890625, 0.703125 0.87890625)) |
+--------------------------------------------------------------------------------------------------------------------+