Understanding How to Query Nested JSON Arrays in Snowflake

Learn how to effectively query nested JSON data stored in arrays within Snowflake using simple steps and explanations.
---

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Snowflake Querying Nested JSON stored as an Array

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Understanding How to Query Nested JSON Arrays in Snowflake

In the world of data management, JSON is often used to represent complex data structures, including arrays and nested objects. When using Snowflake, querying such structures can present challenges, especially when it comes to filtered results. In this guide, we will address a common problem faced by many Snowflake users: how to query nested JSON data stored in an array, specifically focusing on checking for a condition in nested properties.

The Problem

Imagine you've created a table in Snowflake that contains an array of objects in the form of JSON. You wish to extract specific information based on criteria from within that nested structure. Here's the scenario:

You have executed the following query to create a table named PROVIDER_TABLE_V8 that holds nested JSON like this:

[[See Video to Reveal this Text or Code Snippet]]

Now you want to find all rows where the property present equals 1 for a specified name, but are unsure how to achieve this due to the nested structure making it seemingly complex.

The Solution

To navigate this JSON data and query it effectively, Snowflake provides functions that allow you to interact with the data as if it were more structured. Here’s a step-by-step guide on how to do it:

Step 1: Create a Table to Store JSON Data

You start by creating a table that can hold the JSON data as a VARIANT type, which can store semi-structured data.

[[See Video to Reveal this Text or Code Snippet]]

Step 2: Insert Your Data

Next, you need to insert your JSON data into the table. Use the parse_json function to ensure that the data is stored in a format that Snowflake can understand.

[[See Video to Reveal this Text or Code Snippet]]

Step 3: View the Raw Data

To see how the data looks, execute a simple SELECT statement:

[[See Video to Reveal this Text or Code Snippet]]

Step 4: Flatten the JSON Array

Using the LATERAL FLATTEN function, you can extract individual objects from the array. This function allows you to treat the array as a set of rows.

[[See Video to Reveal this Text or Code Snippet]]

Step 5: Filter the Data

To find specific rows where the present property equals 1, you can modify your flatten query with a WHERE clause as follows:

[[See Video to Reveal this Text or Code Snippet]]

Step 6: Clean Up and Alias Your Results

For better readability and structure, you can clean up the results by aliasing the columns and selecting only the necessary data:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

Querying nested JSON data in Snowflake may seem daunting at first, but by utilizing the features provided within the platform, such as VARIANT type for semi-structured data, and the LATERAL FLATTEN function, you can easily extract the information you need. By following the steps outlined in this guide, you can efficiently filter your JSON arrays and retrieve your desired results with clarity and precision.

Final Thoughts

As you work with nested JSON in Snowflake, remember that practice is key. Get hands-on experience by testing various queries and structures, and soon you’ll feel confident in managing complex datasets. If you have questions or need further assistance, don't hesitate to reach out to the Snowflake community!