distinct in mysql is not working.

Question

1.00/5 (1 vote)

See more:

Hi friends,

In my MySQL query distinct is not working properly.I am getting duplicate records at the time of retrieving records.

code:

SQL

SELECT DISTINCT  slip_header_trn.slip_no, slip_header_trn.com_cd, slip_header_trn.cust_cd, slip_header_trn.entry_div, slip_header_trn.dest_cd, slip_header_trn.est_date,slip_header_trn.entry_date,slip_header_trn.order_date,slip_header_trn.delivery_comp_date, slip_header_trn.status_cd, slip_details_trn.model_cd, slip_details_trn.item_cd, model_mst.model_nm, destination_mst.dest_name, customer_mst.cust_nm, user_mst.user_nm, supplier_mst.sup_nm, company_mst.com_name FROM slip_header_trn LEFT OUTER JOIN slip_details_trn ON slip_header_trn.slip_no = slip_details_trn.slip_no LEFT OUTER JOIN customer_mst ON slip_header_trn.cust_cd = customer_mst.cust_cd LEFT OUTER JOIN destination_mst ON slip_header_trn.dest_cd = destination_mst.dest_cd LEFT OUTER JOIN supplier_mst ON slip_details_trn.sup_cd = supplier_mst.sup_cd LEFT OUTER JOIN user_mst ON slip_header_trn.user_id = user_mst.user_id  LEFT OUTER JOIN model_mst ON slip_details_trn.model_cd = model_mst.model_cd LEFT OUTER JOIN company_mst ON slip_header_trn.com_cd = company_mst.com_cd WHERE slip_header_trn.del_flg = 0

Posted 12-Sep-11 19:09pm

josh-jw

Updated 12-Sep-11 20:12pm

Prerak Patel

v3

Add a Solution

Comments

Mehdi Gholam 13-Sep-11 1:10am

Post your code

Pravin Patil, Mumbai 13-Sep-11 1:19am

Maybe you are using Distinct wrongly. Post your query..

Prerak Patel 13-Sep-11 2:13am

Added code block.

Herman<T>.Instance 13-Sep-11 3:55am

with all these LEFT OUTER JOINS......you are begging for duplicates

1 solution

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)

Morgs Morgan · Accepted Answer · 2011-09-12T21:40:00

Hi,

According to my knowledge on DISTINCT usage, for better and indeed distinct results you have to "Project One Column" on your table!

You are giving your database alot of work/overhead to try and perform a distinct search on more 10 columns as per query posted. It's good practice to sometimes target integer, char columns or columns with less data.

Just imagine if your boss asked you to code in more than 10 languages at the same time? you may ofcourse know more than 10 languages but your performance will drop-dead and the results may be not as expected - exactly why you are still getting duplicate rows in your query that is using DISTINCT! coz it's just as confused as u would be...

Good luck.