2024-12-06
639 reads
Subquery
Three Use Case Examples for SQL Subqueries
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
2019-11-08
1,153 reads
SQL Server Subquery in Select Statement with Where Clause
In this part of the temporary data store tip series we look at using subqueries to select data as well as how to use for inserts, updates and deletes.
2019-05-22
Stairway to T-SQL: Beyond The Basics Level 3: Building a Correlated Subquery
This stairway level will expand on the subquery topic by discussing a type of subquery known as a correlated subquery, and explores what a correlated subquery is and how it is different from a normal subquery.
2019-05-08 (first published: 2014-03-05)
20,715 reads
2013-05-09
2,261 reads
2013-03-08
2,382 reads
2013-01-11
2,732 reads
2011-09-19
3,168 reads
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Question of the Day
Finding Trailing Spaces
I have some data in a SQL Server 2025 database. It looks like this for the dbo.Customer table:
CustomerID CustomerName PreferredName 1 Steve Steve 2 Andy Andy 3 Brian Brian 4 Allan Allan 5 Devin Devin 6 Steve Steve 7 Sally SallyI want to detect which names have a single trailing space. The CustomerName is a varchar() and the PreferredName is a CHAR(). Does this query detect the problem rows?
SELECT
CustomerID,
CustomerName,
PreferredName
FROM Customer
WHERE CustomerName <> RTRIM(CustomerName)
OR PreferredName <> RTRIM(PreferredName); See possible answers 