How to Convert Struct type to Columns in Spark

I have a Spark DataFrame with StructType and would like to convert it to Columns, could you please explain how to do it?

Converting Struct type to columns is one of the most commonly used transformations in Spark DataFrame. In order to explain I will create the Spark DataFrame with Struct columns

val structureData = Seq(
    Row(Row("James ","","Smith"),Row(Row("CA","Los Angles"),Row("CA","Sandiago"))),
    Row(Row("Michael ","Rose",""),Row(Row("NY","New York"),Row("NJ","Newark"))),
    Row(Row("Robert ","","Williams"),Row(Row("DE","Newark"),Row("CA","Las Vegas"))),
    Row(Row("Maria ","Anne","Jones"),Row(Row("PA","Harrisburg"),Row("CA","Sandiago"))),
    Row(Row("Jen","Mary","Brown"),Row(Row("CA","Los Angles"),Row("NJ","Newark")))

val structureSchema = new StructType()
    .add("name",new StructType()
    .add("address",new StructType()
      .add("current",new StructType()
      .add("previous",new StructType()

val df = spark.createDataFrame(

From the above example, df.printSchema() yields the below output.

 |-- name: struct (nullable = true)
 |    |-- firstname: string (nullable = true)
 |    |-- middlename: string (nullable = true)
 |    |-- lastname: string (nullable = true)
 |-- address: struct (nullable = true)
 |    |-- current: struct (nullable = true)
 |    |    |-- state: string (nullable = true)
 |    |    |-- city: string (nullable = true)
 |    |-- previous: struct (nullable = true)
 |    |    |-- state: string (nullable = true)
 |    |    |-- city: string (nullable = true)

As you see, the above DataFrame schema consists of two struct columns name and address. Let’s convert name struct type these into columns.

val df2 ="name.*"),
val df2Flatten = df2.toDF("fname","mename","lname","currAddState",

The above example converts the Spark DataFrame struct column into multiple columns.

 |-- name_firstname: string (nullable = true)
 |-- name_middlename: string (nullable = true)
 |-- name_lastname: string (nullable = true)
 |-- address_current_state: string (nullable = true)
 |-- address_current_city: string (nullable = true)
 |-- address_previous_state: string (nullable = true)
 |-- address_previous_city: string (nullable = true)

|fname   |mename|lname   |currAddState|currAddCity|prevAddState|prevAddCity|
|James   |      |Smith   |CA          |Los Angles |CA          |Sandiago   |
|Michael |Rose  |        |NY          |New York   |NJ          |Newark     |
|Robert  |      |Williams|DE          |Newark     |CA          |Las Vegas  |
|Maria   |Anne  |Jones   |PA          |Harrisburg |CA          |Sandiago   |
|Jen     |Mary  |Brown   |CA          |Los Angles |NJ          |Newark     |

In case you wanted to Flatten many struct columns automatically, refer to this page.

Hope this helps !!

Naveen (NNK)

I am Naveen (NNK) working as a Principal Engineer. I am a seasoned Apache Spark Engineer with a passion for harnessing the power of big data and distributed computing to drive innovation and deliver data-driven insights. I love to design, optimize, and managing Apache Spark-based solutions that transform raw data into actionable intelligence. I am also passion about sharing my knowledge in Apache Spark, Hive, PySpark, R etc.

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