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Live webinar - Prioritizing security: Essential strategies for IT leaders

In today's rapidly evolving landscape, managing the security of large and complex database estates is a critical challenge for organizations. Join us for a webinar on Nov 21 covering “Prioritizing security: Essential strategies for IT leaders,” where Redgate’s security experts will share their tips on how you can safeguard your database estate and minimize reputational risk. There will also be a Q&A session where you can get expert advice from our panelists.

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PASS Summit Time

As the Simple Talk Editor, I have had the privilege of attending numerous conferences these past few years, and all of them have been somewhere between great and amazing. Still, there is something a bit more special about the PASS Summit. Even before I started this position, I have been to the PASS Summit events […]

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What's New for the Microsoft Data Platform

By Steve Jones - SSC Editor

Comments posted to this topic are about the item What's New for the Microsoft...

Using Outer Joins

By Steve Jones - SSC Editor

Comments posted to this topic are about the item Using Outer Joins

Closest to ProcDate

By boehnc

Not sure I have this 2nd left join correct. I need to grab the...

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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

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