renaming Array struct columns
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
case class ElementCaseClass(contrast_ratio: Double, error_text: String, error_x_position: Long, error_x_size: Long) | |
val dataset = Seq( | |
(Array( | |
ElementCaseClass(1.0d, "error1", 1L, 2L), | |
ElementCaseClass(2.0d, "error2", 100L, 101L), | |
ElementCaseClass(3.0d, "error3", 1000L, 1001L) | |
)) | |
).toDF("elements") | |
dataset.printSchema() | |
/* | |
root | |
|-- elements: array (nullable = true) | |
| |-- element: struct (containsNull = true) | |
| | |-- contrast_ratio: double (nullable = false) | |
| | |-- error_text: string (nullable = true) | |
| | |-- error_x_position: long (nullable = false) | |
| | |-- error_x_size: long (nullable = false) | |
*/ | |
// As you can see, 'element' is printed instead of 'ElementCaseClass' | |
case class Results(ratio: Double, text: String, x: Long, size: Long) | |
val resultsSchema = ScalaReflection.schemaFor[Results].dataType.asInstanceOf[StructType] | |
dataset.select($"elements".cast(ArrayType(resultsSchema))).printSchema() | |
/* | |
root | |
|-- elements: array (nullable = true) | |
| |-- element: struct (containsNull = true) | |
| | |-- ratio: double (nullable = false) | |
| | |-- text: string (nullable = true) | |
| | |-- x: long (nullable = false) | |
| | |-- size: long (nullable = false) | |
*/ | |
// Array fields are renamed | |
dataset.select($"elements".cast(ArrayType(resultsSchema))).write.mode("overwrite").json("/tmp/test-array-json") | |
/* | |
{"elements":[{"ratio":1.0,"text":"error1","x":1,"size":2},{"ratio":2.0,"text":"error2","x":100,"size":101},{"ratio":3.0,"text":"error3","x":1000,"size":1001}]} | |
*/ | |
// Output doesn't have the idea of the underlying struct name |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment