Azure SQL JSON Documents: Step-by-Step Guide

Implementing JSON documents in Azure SQL involves several steps, from setting up your Azure SQL Database to creating tables designed to store JSON data, and finally querying and manipulating JSON data within those tables. Azure SQL Database supports storing and querying JSON data, enabling you to integrate complex data structures seamlessly with your relational data. Below is a step-by-step guide on how to work with JSON documents in Azure SQL:

1. Set Up Azure SQL Database

First, ensure you have an Azure SQL Database created and configured in your Azure account.

Log in to the Azure Portal.
Create a new SQL database if you haven't already, by navigating to SQL databases -> Add.
Configure your database settings according to your requirements (e.g., select or create a new resource group, specify database name, server, and compute + storage settings).
Review and create the database.

2. Connect to Your Database

Use SQL Server Management Studio (SSMS), Azure Data Studio, or any preferred database tool to connect to your Azure SQL Database.

Open your database tool.
Connect to your Azure SQL database using the server name, database name, and authentication details provided in the Azure portal.

3. Create a Table to Store JSON Documents

You'll need a table with a column specifically designed to hold JSON data. Azure SQL stores JSON data in columns with the NVARCHAR type.

CREATE TABLE JsonDocuments (
    Id INT IDENTITY PRIMARY KEY,
    JsonData NVARCHAR(MAX) CHECK (ISJSON(JsonData) > 0)
);

This table includes a CHECK constraint to ensure only valid JSON data is inserted into the JsonData column.

4. Insert JSON Documents

Insert JSON data into your table using standard SQL INSERT statements. Ensure the JSON data is correctly formatted as a string.

INSERT INTO JsonDocuments (JsonData)
VALUES (N'{"name": "John Doe", "age": 30, "interests": ["football", "coding"]}');

5. Query JSON Data

You can query JSON data directly using the OPENJSON function or by using JSON functions like JSON_VALUE and JSON_QUERY.

Query specific properties using JSON_VALUE:

  SELECT JSON_VALUE(JsonData, '$.name') AS Name
  FROM JsonDocuments;

Query to return a JSON fragment using JSON_QUERY:

  SELECT JSON_QUERY(JsonData, '$.interests') AS Interests
  FROM JsonDocuments;

Transform JSON data into a set of rows using OPENJSON:

  SELECT *
  FROM OPENJSON((SELECT JsonData FROM JsonDocuments))
  WITH (name NVARCHAR(50) '$.name', age INT '$.age');

6. Update JSON Data

Use the JSON_MODIFY function to update JSON data stored in a column.

UPDATE JsonDocuments
SET JsonData = JSON_MODIFY(JsonData, '$.age', 31)
WHERE JSON_VALUE(JsonData, '$.name') = 'John Doe';

7. Indexing JSON Data

For performance, you can create indexes on properties inside the JSON document using computed columns.

ALTER TABLE JsonDocuments
ADD Name AS JSON_VALUE(JsonData, '$.name');

CREATE INDEX idx_name ON JsonDocuments(Name);

This creates a computed column Name extracted from the JSON data and then indexes that column.

Conclusion

By following these steps, you can effectively store, query, and manage JSON documents in Azure SQL, leveraging the flexibility of JSON combined with the power and security of a relational database system. Remember, while Azure SQL provides robust support for JSON data, it's crucial to consider data modeling and indexing strategies to optimize performance and storage.

Step-by-Step Guide to Working with JSON Documents in Azure SQL