Subqueries

External Article

Three Use Case Examples for SQL Subqueries

  • Article

There are many great tutorials on syntax, performance, and keywords for invoking subqueries. However, I wish to discover a tip highlighting selected SQL subquery use cases. Please briefly describe three SQL subquery use case examples. For each use case, cover how a subquery interacts with outer queries and the T-SQL for implementing the use case. Review excerpts from each example to show the value of implementing the use case.

2023-04-14

Blogs

AI: Blog a Day – Day 4: Transformers – Encoder, Decoder, and Attention

By

Continuing from Day 3 where we covered LLM models open/closed and their parameters, Today...

Flyway Tips: Multiple Projects

By

One of the nice things about Flyway Desktop is that it helps you manage...

What DevOps Look Like in Microsoft Fabric

By

Microsoft Fabric (not to be confused with the more general term “fabric” in DevOps)...

Read the latest Blogs

Forums

Can an Azure App Service Managed Identity be used for SQL Login?

By jasona.work

I'm fairly certain I know the answer to this from digging into it yesterday,...

Azure Synapse database refresh

By Sreevathsa Mandli

Hi Team, I am trying to refresh the Azure Synapse Dedicated pool from production...

how to write this query?

By water490

hi everyone I am not sure how to write the query that will produce...

Visit the forum

Question of the Day

Fun with JSON I

I have some data in a table:

CREATE TABLE #test_data
(
    id INT PRIMARY KEY,
    name VARCHAR(100),
    birth_date DATE
);

-- Step 2: Insert rows  
INSERT INTO #test_data
VALUES
(1, 'Olivia', '2025-01-05'),
(2, 'Emma', '2025-03-02'),
(3, 'Liam', '2025-11-15'),
(4, 'Noah', '2025-12-22');
If I run this query, how many rows are returned?
SELECT *
FROM OPENJSON(
     (
         SELECT t.* FROM #test_data AS t FOR JSON PATH
     )
             ) t;

See possible answers