Differences between Left Join and Left Outer Join ?

Question

2.33/5 (2 votes)

See more:

SQL

SQL-Server

can any one explain the differences between left and Left outer join ? (In all Perspectives like performance etc...)

Posted 2-Jan-14 21:32pm

coded007

Add a Solution

Comments

dan!sh 3-Jan-14 3:35am

Here[^]

CPallini 3-Jan-14 3:38am

(virtual) 5.

coded007 3-Jan-14 4:02am

I know that d@nish but i didn't find any performance..... like this but it has it not clear

CPallini 3-Jan-14 3:39am

Don't be afraid of using Google or reading the documentation.

coded007 3-Jan-14 4:04am

I read some where it differs while inserting bulk data and searching BOL files. I need explanation for this

Jain Nishant 3-Jan-14 4:20am

Both of them are same...

thatraja 3-Jan-14 4:31am

Agree the above comment, no difference. Same

coded007 3-Jan-14 6:27am

Dear All, Please find the link with respect i have doubt

http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=100403

CHill60 3-Jan-14 15:33pm

Why does that link give you a doubt? Everyone there is saying there simply is no difference between the two. In terms of performance it will take you longer to type "left outer join" than to type "left join"

coded007 6-Jan-14 1:54am

so it is saying that there will be little bit change in terms of performance. am I right ?

CHill60 6-Jan-14 7:40am

Nowhere in the link http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=100403[^] could I find anything about a change in performance. There is no difference between 'left outer join' and 'left join'

coded007 6-Jan-14 9:24am

Please check the answer quoted by "Tharindu" he said that there will be a performance difference is it true ?

CHill60 6-Jan-14 13:39pm

No he has not. His English is quite poor but I believe he is saying that he cannot find out for definite, but hopes there is no performance difference. See the response immediately after from 'elancaster'. Tharindu did not post a solution, he posted a questionable comment

coded007 6-Jan-14 19:28pm

Ok then! Thanks for postings.......

3 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Sergey Vaselenko · Accepted Answer · 2014-01-02T21:39:00

Solution 1

These are synonyms.

See http://technet.microsoft.com/en-us/library/ms187518(v=sql.105).aspx[^]

Posted 2-Jan-14 21:39pm

Sergey Vaselenko

Comments

Maciej Los 3-Jan-14 5:30am

+5!

Maciej Los · Accepted Answer · 2014-01-02T22:18:00

TechNet of Microsoft wote:
SQL Server uses the following ISO keywords for outer joins specified in a FROM clause:

LEFT OUTER JOIN or LEFT JOIN
RIGHT OUTER JOIN or RIGHT JOIN
FULL OUTER JOIN or FULL JOIN

source: Using Outer Joins[^]

LEFT JOIN and LEFT OUTER JOIN has the same meaning to MS SQL server.

Here is an excellent article about joins: Visual Representation of SQL Joins[^] which ight help you to understand how it works!

TrushnaK · Accepted Answer · 2014-01-02T23:00:00

Solution 3

There is absolutely no difference between LEFT JOIN and LEFT OUTER JOIN. The same is true for RIGHT JOIN and RIGHT OUTER JOIN. When you use LEFT JOIN keyword in SQL Server, it means LEFT OUTER JOIN only.

Both are same. The word OUTER is optional

refer this:-
http://blog.sqlauthority.com/2009/04/13/sql-server-introduction-to-joins-basic-of-joins/[^]

Posted 2-Jan-14 23:00pm

TrushnaK

Comments

Maciej Los 3-Jan-14 5:30am

+5!

TrushnaK 3-Jan-14 5:41am

thanks Maciej.....

Differences between Left Join and Left Outer Join ?

3 solutions

Solution 1

Solution 2

Solution 3

Add your solution here

Preview 0

Existing Members

...or Join us