Databricks Data Engineer Associate Question 177
Select 3You are working with a Delta table in Databricks containing a column named event_data that stores JSON strings. You need to parse the JSON strings into a struct to extract individual fields for further analysis. Which of the following approaches can you use to accomplish this?
- A
Use the
from_jsonfunction with the appropriate schema definition. - B
Use the
to_jsonfunction to convert the JSON string into a struct. - C
Apply the
from_jsonfunction and provide a schema as a string or StructType. - D
Leverage the
explodefunction to parse the entire JSON string into a struct. - E
Use the
selectExprmethod with a SQL-like expression to parse the JSON into a struct.
Show answer and explanation
Correct answers: A, C, E
Explanation
To parse JSON strings into structs in Databricks, the most common approach is using the from_json function with a defined schema. This can be done programmatically or using SQL-like expressions within the selectExpr method. The to_json function is for the reverse operation, and the explode function is unrelated to JSON parsing. Understanding these differences is critical for implementing the correct transformation in Databricks.
- A. Correct.
Correct: The
from_jsonfunction is specifically designed to parse JSON strings into structs when provided with a schema. - B. Incorrect.
Incorrect: The
to_jsonfunction converts structs or other data types into JSON strings, not the other way around. - C. Correct.
Correct: The
from_jsonfunction works when given a schema, which can be defined as a string or a StructType object. - D. Incorrect.
Incorrect: The
explodefunction is used to expand arrays or maps into multiple rows, not to parse JSON strings into structs. - E. Correct.
Correct: The
selectExprmethod can be used to parse JSON strings into structs by applying SQL-like expressions such asfrom_json(event_data, schema).