Data Engineering Associate with Databricks Practice Exam

What is the correct SQL syntax to unpack JSON data into a table view?

1. SELECT json.* FROM table

2. EXPAND json ON table

3. UNPIVOT json FROM table

4. FLATTEN json FROM table

The correct answer is: SELECT json.* FROM table

The correct syntax for unpacking JSON data into a table view is to use the first choice, which effectively leverages the capability to access nested fields directly. In SQL, especially in systems that support JSON functions, using the star operator (json.*) allows you to select all keys and their corresponding values from a JSON column in a table. This option enables the retrieval of structured data from the JSON object and presents it in a tabular format. By using this approach, the individual attributes stored within the JSON structure are directly unpacked and made accessible in the result set. The other options highlight different techniques that do not accurately apply to unpacking JSON. While expanding or unpivoting data can be useful in other contexts, they do not specifically target JSON syntax in SQL. FLATTEN is commonly used in some data processing contexts, especially within tools like Databricks, but its syntax and function relate to a specific implementation rather than the general SQL syntax, which makes it less appropriate in this instance.