Whats the difference between an INNER JOIN and a WHERE clause

If I have
From
table Sales A
INNER JOIN table Salespeople B
ON
A.SalesID = B.SalesID

Then what are the pro/cons of doing the below instead
table Sales A, table SalespeopleB
Where
A.SalesID = B.SalesID
upobDaPlayaAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

pinaldaveCommented:
For inner join there is no difference if you put condition in where or join statement.

It differs for outer join.
0
Éric MoreauSenior .Net ConsultantCommented:
a where clause is to filter out rows that you don't need.

Join is used to get data from other tables.

if you use a INNER join, that means that the link to the second must return data in order for the data of the first table to be returned.

a LEFT (or RIGHT) join does not filter out.
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
upobDaPlayaAuthor Commented:
Which is more efficient...
0
The Ultimate Tool Kit for Technolgy Solution Provi

Broken down into practical pointers and step-by-step instructions, the IT Service Excellence Tool Kit delivers expert advice for technology solution providers. Get your free copy for valuable how-to assets including sample agreements, checklists, flowcharts, and more!

Éric MoreauSenior .Net ConsultantCommented:
they are different. If you can avoid going to the second table, it will be more efficient but sometimes you don't have all the data in the first table to filter out unwanted rows
0
pinaldaveCommented:
Both will give you the same performance in the case of SQL Server when you use INNER JOIN.
0
Éric MoreauSenior .Net ConsultantCommented:
I looked back at your 2 queries. The second one is using the old syntax.

As said by pinaldave, in this very specific case, both queries will perform exactly the same. If you check the Execution plan for both queries (from SSMS), you would find that the SQL engine transforms the second query in the same format as the first one.
0
upobDaPlayaAuthor Commented:
Thanks was always wondering on the above so thanks for answering
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Microsoft SQL Server

From novice to tech pro — start learning today.