🔄 How to Perform Cross Database Queries Using Serverless SQL Pool - Azure Synapse Analytics Tutorial

In Azure Synapse Analytics, Serverless SQL Pool supports querying across multiple databases in the same Synapse workspace. This is useful for combining data from different departments, functional areas, or staging/production environments without physically moving the data.

🧠 What Are Cross-Database Queries?

A cross-database query lets you join or query data between two or more databases by fully qualifying the object names using: [DatabaseName].[SchemaName].[TableName]

✅ Use Cases

• Join reporting data from separate databases
• Reference lookup tables maintained in a shared DB
• Access historical logs stored in a different workspace DB

🧪 Example: Join Tables from Two Databases

SELECT a.CustomerID, a.Name, b.TotalSpent
FROM SalesDB.dbo.Customers a
JOIN FinanceDB.dbo.SpendSummary b
    ON a.CustomerID = b.CustomerID;

📌 Things to Remember

• Both databases must reside in the same Synapse workspace
• Use the correct database and schema names
• Cross-database queries are supported only in Serverless SQL Pool (not in Dedicated SQL Pool)

📺 Watch the Full Tutorial

Credit: This blog was created with the help of ChatGPT and Gemini.