CODEWITHSUNDEEP
scalaapache-sparkopenstreetmap
gilianzz
gilianzz

Reputation: 209

Spark reading Open Street Map data and selecting entries

I have OpenStreetMap (OSM) data from a .orc stored in var nlorc of a country for which I am trying to read out data for specific cities. As far as I know, a city entity is defined as a 'relation' in OSM. The nlorc.printSchema() of my data returns the following:

root
 |-- id: long (nullable = true)
 |-- type: string (nullable = true)
 |-- tags: map (nullable = true)
 |    |-- key: string
 |    |-- value: string (valueContainsNull = true)
 |-- lat: decimal(9,7) (nullable = true)
 |-- lon: decimal(10,7) (nullable = true)
 |-- nds: array (nullable = true)
 |    |-- element: struct (containsNull = true)
 |    |    |-- ref: long (nullable = true)
 |-- members: array (nullable = true)
 |    |-- element: struct (containsNull = true)
 |    |    |-- type: string (nullable = true)
 |    |    |-- ref: long (nullable = true)
 |    |    |-- role: string (nullable = true)
 |-- changeset: long (nullable = true)
 |-- timestamp: timestamp (nullable = true)
 |-- uid: long (nullable = true)
 |-- user: string (nullable = true)
 |-- version: long (nullable = true)
 |-- visible: boolean (nullable = true)

As an example, https://www.openstreetmap.org/relation/47798#map=13/51.4373/4.8888 shows that the name of the city is part of "Tags". How can I access the keys of Tags and select specific cities?

Upvotes: 2

Views: 449

Answers (1)

werner
werner

Reputation: 14905

You can use getItem to access the elements of the map:

df = ...
df.filter(df("tags").getItem("name")==="Baarle-Nassau").show()

Upvotes: 2

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