Data Science Essentials

How to Extract / Parse Data from JSON Data using Google Cloud BigQuery SQL

Summarize the challenges of JSON data and share BigQuery SQL code for an example

Andrew Young
3 min readMay 26


As a data scientist, working with JSON (JavaScript Object Notation) data can present several challenges. Here are some common difficulties you might encounter:

  1. Data Structure: JSON data can have complex, deeply nested structures, making it challenging to extract and manipulate specific information.
  2. Data Integrity: JSON data can be prone to inconsistencies or missing values, especially when obtained from multiple sources or generated dynamically.
  3. Schema Evolution: JSON data often evolves over time as new fields are added or existing fields change their structure. Managing schema changes requires careful attention to ensure compatibility and prevent data compatibility issues in downstream analysis or applications.
  4. Large Dataset Handling: When dealing with large JSON datasets, memory and processing requirements can become a challenge. Loading and processing sizable JSON files may require efficient memory management techniques, streaming, or parallel processing to avoid performance bottlenecks.
  5. Unstructured or Semi-structured Data: JSON data may not always adhere to a well-defined schema or structure. Dealing with unstructured or semi-structured JSON data can be more challenging than working with structured data, as it requires additional efforts for data cleansing and extraction.
  6. Data Validation: Verifying the correctness, consistency, and validity of JSON data can be crucial. Performing data validation checks, such as ensuring the data conforms to expected patterns or constraints, can help identify anomalies or data quality issues.
  7. Performance Considerations: Depending on the programming language or tools you use, parsing and processing JSON data can be computationally expensive. Optimizing code, utilizing appropriate libraries or frameworks, and leveraging indexing or caching techniques can improve performance.
  8. Data Security: JSON data, especially when…