Dharmendra Keshari

Dharmendra is a SQL Server/Microsoft Data Platform professional with over eight years of experience. He enjoys helping others in the SQL Server community and does this by contributing on blogs, speaking at several SQL events. His passion and focus is to explore and share more and more on SQL Server.

Blogs

AI Innovation in Microsoft Keynote

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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

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

PASS Summit 2024 – A Very Different World

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

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Looking for Professional Company Logo Design in New York, USA?

By Emma1100

Look no further than Web Inventix, where we specialize in creating logos that capture...

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

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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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