Databricks Data Engineer Associate Question 186
Single answerYou are working with a dataset in a Databricks notebook that contains a column 'items' with an array of structs, where each struct represents an item with its details (e.g., name and price). You need to generate a new row for each item in the array while retaining the other columns in the dataset. Which function should you use?
- A
explode
- B
flatten
- C
collect_list
- D
groupBy
Show answer and explanation
Correct answer: A
Explanation
The explode function is the correct choice because it is specifically designed to transform an array or map column into multiple rows, where each row corresponds to an element in the array. This functionality is essential for scenarios where you need to 'unpack' an array into individual rows while preserving the structure of the rest of the dataset.
- A. Correct.
The explode function is used to create a new row for each element in an array or map column, which matches the requirement of generating a new row for each item in the 'items' array.
- B. Incorrect.
The flatten function is used to merge multiple arrays into a single array, but it does not create new rows. This does not meet the requirement of generating a new row for each item.
- C. Incorrect.
The collect_list function is used to aggregate values into an array, which is the opposite of what is required in this scenario. It combines rows into a single array rather than splitting them.
- D. Incorrect.
The groupBy function is used for grouping data based on one or more columns, which is unrelated to the requirement of creating a new row for each item in the array.