SQL Window Functions Series: LAG() and LEAD()
Dive deep into the powerful SQL window functions, LAG() and LEAD(). Explore their intricacies, discover real-world examples, and avoid common pitfalls.
2023-12-11
9,578 reads
Date computation
Combine DATE and TIME to DATETIME2 in SQL Server
The most common method on the internet for combining DATE and TIME columns in SQL Server is incorrect. This article demonstrates why that and other methods are incorrect and two lesser known high performance methods that produce correct results even for the "edge cases".
2023-08-07
24,090 reads
How to Find the Start and End Dates for the Current Week (and more)
Learn to calculate Start / First of Week, End of Week, Start of Next Week, Year, Quarter, and Month of the week, Week Numbers and more in T-SQL (Jeff Moden)
2022-07-13
34,085 reads
Add working days but avoid holidays
A function to add or subtract working days taking into account weekends and using a table of non-working days.
2019-07-10 (first published: 2019-06-26)
5,215 reads
2018-02-23 (first published: 2018-02-19)
161 reads
2017-12-29
1,092 reads
Compute Holiday Day of the Month for any Year
This script provides the day of the month for the standard bank holidays for any given year. This is especially useful for computing the workday after a holiday.
2017-05-24 (first published: 2017-05-10)
503 reads
Blogs
AI: Blog a Day – Day 5: Notebooks, Hugging face models and Fine Tuning
By Vinay Thakur
Continuing from Day 4 where we learned Encoder, Decoder, and Attention Mechanism, today we...
AI: Blog a Day – Day 4: Transformers – Encoder, Decoder, and Attention
By Vinay Thakur
Continuing from Day 3 where we covered LLM models open/closed and their parameters, Today...
Flyway Tips: Multiple Projects
By Steve Jones
One of the nice things about Flyway Desktop is that it helps you manage...
Forums
Can an Azure App Service Managed Identity be used for SQL Login?
I'm fairly certain I know the answer to this from digging into it yesterday,...
Azure Synapse database refresh
Hi Team, I am trying to refresh the Azure Synapse Dedicated pool from production...
how to write this query?
hi everyone I am not sure how to write the query that will produce...
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