Databricks Data Engineer Associate Question 178
Single answerYou are working with a JSON dataset in Databricks where each record contains a 'user' field as a JSON string. You need to parse this field into a struct type within a DataFrame for easier downstream processing. Which of the following options will correctly parse the 'user' field into a struct?
- A
Use the
from_jsonfunction with the correct schema and apply it to the 'user' column. - B
Use the
to_jsonfunction with the correct schema and apply it to the 'user' column. - C
Use the
explodefunction on the 'user' column to parse it into a struct. - D
Use the
json_tuplefunction to parse the 'user' column into a struct.
Show answer and explanation
Correct answer: A
Explanation
The from_json function is the appropriate choice when parsing JSON strings into a struct type in Databricks. It requires the JSON string column and the schema of the desired struct as inputs. Other functions, such as to_json, explode, and json_tuple, serve different purposes and are not suitable for this use case.
- A. Correct.
Correct. The
from_jsonfunction is specifically designed to parse JSON strings into a struct or other complex types when provided with a schema. - B. Incorrect.
Incorrect. The
to_jsonfunction is used to convert a struct or map type into a JSON string, not the other way around. - C. Incorrect.
Incorrect. The
explodefunction is used to transform array or map columns into multiple rows, and it does not parse JSON strings. - D. Incorrect.
Incorrect. The
json_tuplefunction extracts individual fields from a JSON string as separate columns, but it does not convert the entire JSON string into a struct.