Our training courses

Book any course as classroom, onsite or online training, or as one-to-one consultancy
Excel Training Basic Excel Advanced Excel VBA Macros Office Scripts Excel Introduction Excel Intermediate Excel Advanced Excel Business Modelling Excel VBA macros Advanced VBA Fast track Excel VBA Basic Office Scripts Advanced Office Scripts Power Platform Training Pure Power BI DAX and fast-track Power Automate Power Apps Introduction to Power BI Adv. Power BI Reports Adv. Power BI Data DAX for Power BI Fast track Power BI Fast track Power BI/DAX Power Automate Desktop Basic Power Automate Advanced Power Automate Fast track Power Automate Power Apps Programming and AI SQL training Visual C# training Python training AI training Introduction to SQL Advanced SQL Fast track SQL Introduction to MySQL Introduction to Visual C# Intermediate C# Fast track C# Introduction to Python Advanced Python Fast track Python Using AI tools Using the OpenAI API SQL Server training Reporting Services Report Builder Integration Services Azure / SSAS Reporting Services Advanced SSRS Fast track SSRS Report Builder Introduction to SSIS Advanced SSIS Fast track SSIS SQL in Azure Data Studio SSAS - Tabular Model
Other training resources

Free resources

Read our blogs, tips and tutorials

Try our exercises or test your skills

Watch our tutorial videos or shorts

Take a self-paced course

Read our recent newsletters

Paid services

License our courseware

Book expert consultancy

Buy our publications

Getting help

Get help in using our site
Our training venues

Where we are

London

Manchester

Where you are

Across the UK

At your site

Online

At your computer
Why we are different

Transparent reviews

546 attributed reviews in the last 3 years

Delivery of courses

Refreshingly small course sizes

Outstandingly good courseware

Whizzy online classrooms

Wise Owl trainers only (no freelancers)

Nicer to work with

Almost no cancellations

We have genuine integrity

We invoice after training

Reliable and established

Review 30+ years of Wise Owl

View our top 100 clients

Search our website

GO
+44 (161) 883 3606 sales@wiseowl.co.uk Web enquiry form
We also send out useful tips in a monthly email newsletter ...

Sign up to newsletter

Our training courses

AI - Articial Intelligence

Power BI and DAX

Other training resources

Tips and tricks

Guides and tutorials

YouTube tutorials

Test your skills

Self-paced courses

Our training venues

Why we are different

Hundreds of published reviews

Small class sizes

Outstanding courseware

Online classroom

(Almost) no cancellations

Wise Owl trainers only

Genuine integrity

Invoices after training

30+ years of Wise Owl

Our top 100 clients

This page has 2 threads | Add post

Video tutorials

Video tutorials

Finding our videos useful? Please consider helping us to share more!

Selecting data in SQL videos | SQL Queries Part 6 - Using Joins in Queries

Posted by Andrew Gould on 23 May 2012

SQL Queries Part 6 - Using Joins in Queries

Learn how to use joins in Microsoft SQL Server queries. This video teaches you how to include multiple tables in a query using INNER joins, how to find unmatched records using LEFT and RIGHT OUTER joins, and how to use FULL OUTER joins.

See our full range of SQL training resources, or test your knowledge of SQL with one of our SQL skills assessment tests.

This video has the following accompanying files:

File name	Type	Description
Create Movies Database with Genre Table.sql	SQL query
GenerateMoviesDatabase.sql	SQL query
GenerateUpdatedMoviesDatabase.sql	SQL query

Click to download a zipped copy of the above files.

There are no exercises for this video.

Making a video bigger

You can increase the size of your video to make it fill the screen like this:

Full screen view

Play your video (the icons shown won't appear until you do), then click on the full screen icon which appears as shown above.

When you've finished viewing a video in full screen mode, just press the Esc key to return to normal view.

Improving the quality of a video

To improve the quality of a video, first click on the Settings icon:

Settings icon

Make sure yoiu're playing your video so that the icons shown above appear, then click on this gear icon.

Choose to change the video quality:

Changing video quality

Click as above to change your video quality.

The higher the number you choose, the better will be your video quality (but the slower the connection speed):

Different speeds

Don't choose the HD option shown unless your connection speed is fast enough to support it!

Is your Wise Owl speaking too slowly (or too quickly)? You can also use the Settings menu above to change your playback speed.

This page has 2 threads

From:	duggie
When:	07 Oct 20 at 13:26

In the video, around the 9min 48 sec mark, you state you wanted to see everything in the director's table and to do that, you use a LEFT OUTER join.

Imagine if the actor's table didn't exist. If you wanted to see everything in the director's table, would you simply write:

SELECT * FROM tbldirector

If so, even if the actor's table is "brought into the equation", to see everything in the director's table, wouldn't my query work?

On a separate note, if you do have both tables, which part of the venn diagram would be highlighted for this query:

SELECT * FROM tbldirector

From:	Andy B
When:	07 Oct 20 at 13:45

I'm answering on behalf of Andrew, as he's busy training today.

The following two commands are identical:

SELECT * FROM tblDirector

SELECT tblDirector.* FROM tblDirector LEFT OUTER JOIN tblFilm ON tblDirector.DirectorId = tblFilm.DirectorId

The first command will list out all the rows and columns in the director table; the second will do the same thing. The only reason to use the second syntax is if you want either to list out columns from the films table, or use some of them for filtering or grouping.

If you run the first command, I'm not even sure there IS a Venn diagram (and if it is, it's just a circle). What this will list out is all directors, whether or not they've made films.

From:	duggie
When:	07 Oct 20 at 14:48

Thanks for your swift reply.

However, I tried typing your SQL command:

SELECT tblDirector.* FROM tblDirector LEFT OUTER JOIN tblFilm ON tblDirector.DirectorId = tblFilm.DirectorId

but got an error.

Is it my mistake?

From:	Andy B
When:	07 Oct 20 at 15:34

OK, I used the old table names. Try:

SELECT Director.* FROM Director LEFT OUTER JOIN Film ON Director.DirectorId = Film.DirectorId

Reply

Reply

Reply

From:	duggie
When:	21 Oct 17 at 12:23

I find using joins difficult to understand.

In the video, you have:

select
d.directorid,
d.directorname,
f.filmname,
f.filmdirectorid
from
tbldirector as d
inner join tblFilm as f
on d.directorid=f.FilmDirectorID

I prefer the following:

select
d.directorid,
d.directorname,
f.filmname,
f.filmdirectorid
from tbldirector as d
, tblFilm as f
WHERE d.directorid=f.FilmDirectorID

However, I can't seem to do the same for a LEFT JOIN.

I tried to replicate this query

select
d.directorid,
d.directorname,
f.filmname,
f.filmdirectorid
from
tbldirector as d
left join tblFilm as f
on d.directorid=f.FilmDirectorID

by writing this but it returned more results (though I can't be sure if all the records from the query using LEFT JOIN is contained in this query):

select
d.directorid,
d.directorname,
f.filmname,
f.filmdirectorid
from tbldirector as d
, tblFilm as f
WHERE d.directorid=f.FilmDirectorID OR f.FilmDirectorID IS NULL

What is wrong?

From:	Andy B
When:	21 Oct 17 at 12:29

I think the answer to your question is that our way is better! I can't think of a way to use your method to solve the second problem. Although conceptually your method is perhaps easier to understand, I think I would take the time to learn how to write inner and outer joins. Not only are they more flexible (as you have seen), but the vast majority of examples on the Internet use joins.

From:	duggie
When:	22 Oct 17 at 22:07

Andy,

I agree with you that in the long run, it's more beneficial to get accustomed to using JOINS

Out of curiosity for fellow readers, someone on another forum replied with this response to NOT using JOINS:

SELECT d.directorid, d.directorname, f.filmname, f.filmdirectorid
FROM tbldirector AS d, tblFilm AS f
WHERE d.directorid = f.FilmDirectorID
UNION
SELECT d.directorid, d.directorname, null filmname, null filmdirectorid
FROM tbldirector d
WHERE NOT EXISTS (SELECT 1 FROM tblFilm AS f WHERE d.directorid=f.FilmDirectorID);

Reply

Reply

Reply

Head office

Kingsmoor House

Railway Street

GLOSSOP

SK13 2AA

London

Landmark Offices

99 Bishopsgate

LONDON

EC2M 3XD

Manchester

Holiday Inn

25 Aytoun Street

MANCHESTER

M1 3AE

Visual C# training

Excel training courses

Power Automate training

Power BI / DAX training

Python training courses

SQL training courses

VBA (macros) training

© Wise Owl Business Solutions Ltd 2024. All Rights Reserved.

Terms & Conditions

End of small page here

Please be aware that our website uses cookies!

I'm OK with this Tell me more ...