Video:
Subqueries, Nested Queries, and Derived Tables - An Introduction to Advanced SQL Constructs
Skill
level:
300 (Intermediate)- Run Time:
17:27
- Instructor:
Scott Whigham
Description:
Subqueries and derived tables can be some of the hardest constructs for people new to SQL to really grasp. This video is a "First Look"
at sub-selects (another word for sub-queries) and the basic concepts of using subqueries in your SELECT statements. Perhaps the most valuable thing that even
seasoned query-writers will get from watching this video is the "how"; a major focus of this video is how SQL Server processes subqueries internally. Scott Whigham,
author of this site, takes you through how SQL Server will process the subquery in a step-by-step approach.
Note: This video was shot on SQL Server 2005 but the concepts are the same for SQL Server 2000.
Highlights from this video:
- Execution plans: are they different or the same between different subqueries?
- Using a subquery instead of a JOIN and vice-versa
- Correlated subqueries and Simple Subqueries
- Derived Tables; i.e., embedding a SELECT statement in the FROM clause
- Step by step approach to writing subqueries
- SQL Server architecture: Query Processing Sequence
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and watch this video
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Scott Whigham
Scott Whigham is the founder of LearnItFirst.com, one of the web's most extensive
video training libraries focusing on technical training. Scott is also an experienced
consultant, trainer, and author with more than a decade of hands-on experience working
with SQL Server databases, writing and debugging applications using Visual Studio,
and performance tuning. Scott designed the architecture (websites, class libraries,
and database) for the LearnItFirst.com websites and, most
re...
(Scott's full bio can be found here)
NOTE: This video is part of our
SQL Server Programming (SQL Server 2005/2000): Transact SQL course.
This video is from Chapter
9:
Subqueries, Nested Queries, and Derived Tables in Transact SQL
