Transforming JSON Properties in SQL Server: From String to Array

Learn how to update JSON string properties in SQL Server to arrays with our step-by-step guide. Transform your JSON data efficiently!
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Transforming JSON Properties in SQL Server: From String to Array

In the world of database management, handling JSON data within SQL Server can sometimes pose challenges, especially when you need to modify the structure of your JSON objects. One common scenario arises when you want to change a property from a simple string to an array to allow for multiple values. In this guide, we will explore how to achieve this transformation effortlessly.

The Problem: Updating a JSON String Property to an Array

Let's say you have a SQL Server table with a JSON column. Currently, this column contains a property called Code that holds a single string value. However, for many use cases, it's important to convert this property into an array so that it can accommodate multiple strings.

Here’s a quick overview of the changes we want to make:

Current values:

"Code" : null should become "Code" : []

"Code" : "XX" should become "Code" : ["XX"]

This update not only enhances the flexibility of your data but also prepares it for more complex queries and operations in the future.

The Solution: Using SQL Server Functions to Modify JSON

To successfully modify your JSON data within SQL Server, we can utilize the OPENJSON() function in conjunction with JSON_MODIFY(). This powerful combination allows you to extract and manipulate JSON data easily.

Step-by-Step Guide to Update JSON String to Array

1. Sample Data Preparation

We start by creating a sample table with various JSON formats. Here’s how you can set up your test data:

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

2. Updating the JSON Structure

Now that we have our sample data, we will perform the update using the following SQL statement:

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

3. Understanding the SQL Statement

JSON_MODIFY(): This function is used to update the JSON value in our specified path ($.Code).

OPENJSON(): This function helps to parse our JSON and understand the type of the Code property.

OUTER APPLY: This is utilized to join the main table with the results from OPENJSON, enabling a smooth extraction of values for modification.

Resulting Output

After running the update statement, you will notice that the JSON values in the JsonColumn have changed as expected:

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

4. Alternative Approach

Based on suggestions from the community, you could also simplify the update using a slightly modified query, as shown below:

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

Conclusion

Transforming a JSON string property into an array in SQL Server can be done seamlessly with the right approach. By utilizing SQL functions such as OPENJSON() and JSON_MODIFY(), you can handle complex JSON structures efficiently. Whether your application needs more flexibility in managing data or you are preparing for advanced queries, this transformation will set you on the right path.

By following the guide above, you can easily perform this operation across your SQL Server databases, ensuring that your JSON data is both structured and functional.