why this query can delete duplicates ?

Posted on 16th Feb 2014 07:03 pm by admin

why this query can delete duplicates ? Anybody can give me the detailed explanation ?

Thanks

select salary from employees union select salary from employees;

Your Answer:

Login to answer

Other forums

Simple email form - Newbie
Hello all,

First time poster!

I've been asked to create a simple HTML form that submit

imap: how to save a copy of sent emails to sent elements
Hello my friends,

I am writing an online emailing application with inbox outbox/sent elements

how to put the 0-100 numbers into 1.txt and 100-200 into 2.txt ?
how to put the 0-100 numbers into 1.txt and 100-200 into 2.txt and so on 200-300 into file 3.txt ?

How To Make More Than One Redirection with PHP on the same page?
Hey im trying to do a direction page where it open differently link direction pages every time som

BI in Upstream Production operations
Appreciate if you can assist in the following areas:
1) Examples of life before and after BI i

Windows 7
Windows 7 default user account control worries experts. Corporate IT departments should be pleased w

Check Date/Time in PHP
What I need the code to check is that $reQuest is 24 hours in the past then return a time based on h

Passing an array of values From VB6.0 to Oracle PL/SQL Function
Basically we are using VB6.0.

When we try to pass an array from VB6.0 to an Oracle PL/SQL

Asset Transfer from One plant to another within same company code
Hi,

Please advise how to transfer one asset from one plant to another plant within same c

Greek characters in php
Hi,

I'm making a script and I m using for first time greek characters.
I started to write