need help in sql query

Question

0.00/5 (No votes)

See more:

hi all

Can any one explain the sql query how this will execute
means which join will done first on which condition.

SQL

SELECT DISTINCT P.TITLE ,P.PROJECT_ID FROM PROJECT_MEMBER PM 
INNER JOIN PROJECT P ON PM.PROJECT_ID = P.PROJECT_ID
LEFT JOIN PROJECT_LEAD_MAPPING PLM ON PLM.FK_PROJECT_ID = P.PROJECT_ID AND PLM.IS_ACTIVE = 1
WHERE ((PM.MEMBER_ID = 1) OR (PLM.LEADER_ID = 1))
AND P.STATUS = 4
AND PM.START_DATE <= '2012-4-17' AND PM.END_DATE > '2012-4-17'

Please Help

Thanks in advance

Posted 17-Apr-12 2:42am

bhagirathimfs

Updated 17-Apr-12 3:25am

v3

Add a Solution

2 solutions

Solution 1

The query processor in any modern RDBMS will try to optimize the order of execution and this will depend on how much data and what indexes have been defined.

So it is very difficult if not impossible to tell you this without asking the execution plan from the server processing the query.

Posted 17-Apr-12 3:16am

Mehdi Gholam

Comments

Abhinav S 17-Apr-12 9:25am

%!

bhagirathimfs 17-Apr-12 9:27am

Sry didn't get "%!"

Mehdi Gholam 17-Apr-12 9:42am

Thanks %! :)

bhagirathimfs 17-Apr-12 10:42am

:)

bhagirathimfs 17-Apr-12 9:27am

Actually i want to know how this will execute.
Means:1st the inner join will executed with the condition given in the on cluse
or the left outer join will execute first .
Like this how the above query will execute ?

Mehdi Gholam 17-Apr-12 9:44am

Run : explain <your query>
this will show you what the server is doing.

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)

bhagirathimfs · Accepted Answer · 2012-04-17T04:43:00

Solution 2

SQL

Posted 17-Apr-12 4:43am

bhagirathimfs

Updated 17-Apr-12 20:20pm

v3

Comments

member60 18-Apr-12 2:22am

what is this