Articles

Technical Article

You are cordially invited to attend 2021 Virtual Data.SQL.Saturday.LA event!

We are reaching out to all people that enjoyed SQL Saturday in LA 2017, 2018, 2019, and 2020 events to let you know that the 2021 event is fast approaching. Only 30+ days remain until the June 12 Virtual Data.SQL.Saturday.LA event. Please register soon to reserve your spot by using http://2021sqlsatla.eventbrite.com/ hyperlink, register using a form below or just use a QR code.

You rated this post out of 5. Change rating

2021-05-26 (first published: )

SQLServerCentral Article

Dimensionality Reduction Techniques - PCA, Kernel-PCA and LDA Using Python

Summary In this article, we will be looking at some of the useful techniques on how to reduce dimensionality in our datasets. When we talk about dimensionality,  we are referring to the number of columns in our dataset assuming that we are working on a tidy and a clean dataset. When we have many columns […]

4 (1)

You rated this post out of 5. Change rating

2021-05-24

3,869 reads

SQLServerCentral Article

SQL Server 2016 - Always Encrypted

Always Encrypted is a new security feature which was introduced in SQL Server 2016. Always Encrypted is a technology to ensure the data stored in a database remains encrypted at all times during SQL Server query processing. Always Encrypted allows clients to encrypt sensitive data, such as credit card numbers and national identification numbers, inside the […]

4.67 (6)

You rated this post out of 5. Change rating

2021-05-21 (first published: )

13,558 reads

Blogs

AI Innovation in Microsoft Keynote

By

I’m thrilled to be covering the Microsoft Keynote: Fuel AI Innovation with Azure Databases on Day...

Benefits of Migrating from Azure Synapse Analytics to Microsoft Fabric

By

Many customers ask me about the advantages of moving from Azure Synapse Analytics to...

PASS Summit 2024 – A Very Different World

By

The last data centric conference I attended was the PASS Summit in 2019. A...

Read the latest Blogs

Forums

What does B6 Notebook mean?

By learningtoday

B6 Notebook Size can be found in a few novels and stories. The dimensions...

Unencrypted connections in Always on Availability Group

By Awais Afzal

Hi, In my Always On Availability environment, I am seeing two encrypt_option values as...

Error loading multiple CSV files in SSIS

By water490

Hi everyone I have a bunch of CSV files that I need to bulk...

Visit the forum

Question of the Day

Using Outer Joins

I have this data in a SQL Server 2019 database:

Customer table
CustomerID CustomerName
1          Steve
2          Andy
3          Brian
4          Allen
5          Devin
6          Sally

OrderHeader table
OrderID CustomerID OrderDate
1       1          2024-02-01
2       1          2024-03-01
3       3          2024-04-01
4       4          2024-05-01
6       4          2024-05-01
7       3          2024-06-07
8       2          2024-04-07
I want a list of all customers and their order counts for a period of time, including zero orders. If I run this query, how many rows are returned?
SELECT 
  c.CustomerName, COUNT(oh.OrderID)
 FROM dbo.Customer AS c
LEFT JOIN dbo.OrderHeader AS oh ON oh.CustomerID = c.CustomerID
WHERE oh.Orderdate > '2024/04/01'
GROUP BY c.CustomerName

See possible answers