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    API Reference ↗
    Data connectivity & integrationPipeline Builder ExpressionsGeometry array (unary) union

    Geometry array (unary) union

    Supported in: Batch, Streaming

    Given an array of geometries, combine these into a single geometry, merging without overlap.

    Expression categories: Geospatial

    Declared arguments

    • Expression - An array of geometries to union.
      Expression<Array<T>>

    Type variable bounds: T accepts Geometry

    Output type: T

    Examples

    Example 1: Base case

    Argument values:

    • Expression: geometries
    geometriesOutput
    [ {"type":"Polygon","coordinates":[[[0.0,0.0],[0.0,1.0],[1.0,1.0],[1.0,0.0],[0.0,0.0]]]}, {"type":"Polygon","coordinates":[[[0.5,0.0],[1.5,0.0],[1.5,1.0],[0.5,1.0],[0.5,0.0]]]} ]{"type":"Polygon","coordinates":[[[0.0,0.0],[0.0,1.0],[0.5,1.0],[1.0,1.0],[1.5,1.0],[1.5,0.0],[1.0,0.0],[0.5,0.0],[0.0,0.0]]]}
    [ ]null
    nullnull

    Example 2: Base case

    Argument values:

    • Expression: geometries
    geometriesOutput
    [ {"type":"Polygon","coordinates":[[[0.0,0.0],[0.0,1.0],[1.0,1.0],[1.0,0.0],[0.0,0.0]]]}, {"type":"P...{"type":"Polygon","coordinates":[[[0.0,0.0],[0.0,1.0],[1.0,1.0],[1.0,0.0],[0.0,0.0]]]}

    Example 3: Base case

    Argument values:

    • Expression: geometries
    geometriesOutput
    [ {"type":"Polygon","coordinates":[[[0.0,0.0],[0.0,1.0],[1.0,1.0],[1.0,0.0],[0.0,0.0]]]}, {"type":"Polygon","coordinates":[[[5.0,5.0],[5.0,6.0],[6.0,6.0],[6.0,5.0],[5.0,5.0]]]} ]{"type":"MultiPolygon","coordinates":[[[[0.0,0.0],[0.0,1.0],[1.0,1.0],[1.0,0.0],[0.0,0.0]]],[[[5.0,5.0],[5.0,6.0],[6.0,6.0],[6.0,5.0],[5.0,5.0]]]]}

    Example 4: Base case

    Argument values:

    • Expression: geometries
    geometriesOutput
    [ {"type":"Polygon","coordinates":[[[0.0,0.0],[0.0,1.0],[1.0,1.0],[1.0,0.0],[0.0,0.0]]]}, {"type":"Polygon","coordinates":[[[1.0,0.0],[1.0,1.0],[2.0,1.0],[2.0,0.0],[1.0,0.0]]]} ]{"type":"Polygon","coordinates":[[[0.0,0.0],[0.0,1.0],[1.0,1.0],[2.0,1.0],[2.0,0.0],[1.0,0.0],[0.0,0.0]]]}

    Example 5: Base case

    Argument values:

    • Expression: geometries
    geometriesOutput
    [ {"type":"LineString","coordinates":[[0.0,0.0],[1.0,0.0]]}, {"type":"Polygon","coordinates":[[[1.0,0.0],[1.0,1.0],[2.0,1.0],[2.0,0.0],[1.0,0.0]]]} ]{"type":"GeometryCollection","geometries":[{"type":"LineString","coordinates":[[0.0,0.0],[1.0,0.0]]},{"type":"Polygon","coordinates":[[[1.0,0.0],[1.0,1.0],[2.0,1.0],[2.0,0.0],[1.0,0.0]]]}]}

    Example 6: Edge case

    Argument values:

    • Expression: geometries
    geometriesOutput
    [ {"type":"Polygon","coordinates":[[[1.0,0.0],[1.0,1.0],[2.0,1.0],[2.0,0.0],[1.0,0.0]]]}, {"type":"Polygon","coordinates":[[[1.0,0.0],[1.0,1.0],[2.0,1.0],[2.0,0.0],[1.0,0.0]]]} ]{"type":"Polygon","coordinates":[[[1.0,0.0],[1.0,1.0],[2.0,1.0],[2.0,0.0],[1.0,0.0]]]}

    Example 7: Edge case

    Argument values:

    • Expression: geometries
    geometriesOutput
    [ {"type":"Polygon","coordinates":[[[1.0,0.0],[1.0,1.0],[2.0,1.0],[2.0,0.0],[1.0,0.0]]]} ]{"type":"Polygon","coordinates":[[[1.0,0.0],[1.0,1.0],[2.0,1.0],[2.0,0.0],[1.0,0.0]]]}

    Example 8: Edge case

    Argument values:

    • Expression: geometries
    geometriesOutput
    [ {"type":"Polygon","coordinates":[[[1.0,0.0],[1.0,1.0],[2.0,1.0],[2.0,0.0],[1.0,0.0]]]}, {"type":"Polygon","coordinates":[[[1.0,0.0],[1.0,1.0],[2.0,1.0]]]} ]{"type":"Polygon","coordinates":[[[1.0,0.0],[1.0,1.0],[2.0,1.0],[2.0,0.0],[1.0,0.0]]]}