473,699 Members | 2,666 Online
Bytes | Software Development & Data Engineering Community
+ Post

Home Posts Topics Members FAQ

Increasing by percentage

1 New Member
hi

im trying to update one of the records in my table 'City' called 'Population' by 5%.

UPDATE City
SET
Population= Population * 1.05;

The calculation seems correct but its just the final result which seems to not have proper rounding.

for example
one of the records in 'Population' is 1.659.000
after i use the update function my final answer comes out to 1.74195 rather than 1.741.950
Mar 16 '11 #1
1 2474
code green
1,726 Recognized Expert Top Contributor
This is because of the way computers handle floating point numbers.
This is a full lecture on any computer science module and is worth a little research if interested.

Suffice to say do not trust the return values from any calculation or comparison involving floating point numbers.

ROUND seems an obvious solution but this does not work on my system.
I use CAST(.......... .... AS DECIMAL(10,4))
which returns numbers to 4 decimal places.
Mar 16 '11 #2

Sign in to post your reply or Sign up for a free account.

Similar topics

7
2815
by: Conax | last post by:
Hello, This is actually a general programming question but I don't know which newsgroup best to put it so please pardon me. I've always been looking for the best way to get an accurate percentage statistics. For example, in a election scenario:
22
6962
by: Les Juby | last post by:
I am trying to adjust the window/table size of a website (www.worklaw.co.za) which has made use of DIV tags with its settings embedded in an CSS file. The client wants its width and height to adjust according to dynamic screen size, and I have been able to adjust the width to a percentage value which works fine. But if I try do the same with the height it shows some very strange results squashing the field to display about 3 lines.
15
5007
by: Joe Lester | last post by:
I installed Postgres 7.4.1 on a dual processor G5 running Mac OS 10.3.2. I'm trying to increase the max_connections to 300 and running into some trouble. If anyone could shed some light, I'd greatly appreciate it. Here's part of my postgresql.conf: # - Connection Settings - tcpip_socket = true max_connections = 300
0
2038
by: fake ID | last post by:
Since you can't search for these symbols used in asp.net "<%#" or '<%=' I thought i'd post this to make things a little easier to find. Potential search word combinations: -lessthan Percentage symbol hash -lessthan Percentage symbol hash -lessthan Percentage hash -lessthan Percent symbol hash -less than Percentage symbol hash -less than Percentage hash
5
4368
by: James Conrad StJohn Foreman | last post by:
Have found http://www-128.ibm.com/developerworks/db2/library/techarticle/lyle/0110lyle.html which is quite helpful, but doesn't quite tell me what I want. I have a table, advertising_spend with two columns, date and spend. SELECT date, spend, sum(spend) over (order by date) as cumulative_spend FROM advertising_spend WHERE date BETWEEN '01.03.2006' AND '31.03.2006'
6
28090
by: Hacking Bear | last post by:
Hi, I still don't quite fully understand how to handle mixing border/margin pixel width with percentage width. In the example below, I want to place side-by-side two DIV boxes inside a box. 1. Each box takes up 50% of the parent. 2. One of the box has a border width of 1px.
4
5655
by: Micheal | last post by:
Greetings Access Group, Being relatively new to Access, I try to work through problems on my own and have been very successful, although I have a conundrum that I have been working on for two days (total 10 hours) and I have yet to resolve it. please excuse me for my lack of terminology, I will try to provide you with the best of information. I currently have a report that contains 2 totals and the percentage of the difference of the 2...
4
8265
by: Rahul B | last post by:
Hi, I was getting the error: sqlcode: -911 sqlstate: 40001 , which is "The maximum number of lock requests has been reached for the database." So i increased the locklist size to 200 from the default value of 100. I wanted to know what other effects it will have on the database? Like, will the performance reduce, if the locklist size is 200 and 120 locks are on it as compared to when the locklist size is 130 and 120
5
8368
by: Aswanth | last post by:
I'm Using Asp.Net with C# & Working with SSRS 2005 for Generating Reports.. The Following Expression I'm using in Reports to Show the Percentage of Particular Items in REPORT.. =Round((Fields!Clicks.Value*100)/Sum(Fields!Clicks_Show.Value, "DataSet1_Get_All_1234567"),2)& "%" With this Expression I'm Getting Reports Percentage(Total) 100%(NO Problem).. But for Some Reports it is Coming >100 or < 100 Total Percentage (ie 105% or...
0
1048
by: raylopez99 | last post by:
From the Wall Street Journal. RL August 22, 2008, 3:35 pm Windows Vista: Coming Soon to Your Work Computer? Bad news for workers: Some of you may be using Windows Vista sooner than you think. You mean I may have to start using Vista? According to most comments this blog receives – a vocal minority, to
0
8691
marktang
by: marktang | last post by:
ONU (Optical Network Unit) is one of the key components for providing high-speed Internet services. Its primary function is to act as an endpoint device located at the user's premises. However, people are often confused as to whether an ONU can Work As a Router. In this blog post, we’ll explore What is ONU, What Is Router, ONU & Router’s main usage, and What is the difference between ONU and Router. Let’s take a closer look ! Part I. Meaning of...
0
9180
Oralloy
by: Oralloy | last post by:
Hello folks, I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>". The problem is that using the GNU compilers, it seems that the internal comparison operator "<=>" tries to promote arguments from unsigned to signed. This is as boiled down as I can make it. Here is my compilation command: g++-12 -std=c++20 -Wnarrowing bit_field.cpp Here is the code in...
1
8920
by: Hystou | last post by:
Overview: Windows 11 and 10 have less user interface control over operating system update behaviour than previous versions of Windows. In Windows 11 and 10, there is no way to turn off the Windows Update option using the Control Panel or Settings app; it automatically checks for updates and installs any it finds, whether you like it or not. For most users, this new feature is actually very convenient. If you want to control the update process,...
0
8887
tracyyun
by: tracyyun | last post by:
Dear forum friends, With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each protocol has its own unique characteristics and advantages, but as a user who is planning to build a smart home system, I am a bit confused by the choice of these technologies. I'm particularly interested in Zigbee because I've heard it does some...
1
6536
isladogs
by: isladogs | last post by:
The next Access Europe User Group meeting will be on Wednesday 1 May 2024 starting at 18:00 UK time (6PM UTC+1) and finishing by 19:30 (7.30PM). In this session, we are pleased to welcome a new presenter, Adolph Dupré who will be discussing some powerful techniques for using class modules. He will explain when you may want to use classes instead of User Defined Types (UDT). For example, to manage the data in unbound forms. Adolph will...
0
5877
by: conductexam | last post by:
I have .net C# application in which I am extracting data from word file and save it in database particularly. To store word all data as it is I am converting the whole word file firstly in HTML and then checking html paragraph one by one. At the time of converting from word file to html my equations which are in the word document file was convert into image. Globals.ThisAddIn.Application.ActiveDocument.Select();...
0
4378
by: TSSRALBI | last post by:
Hello I'm a network technician in training and I need your help. I am currently learning how to create and manage the different types of VPNs and I have a question about LAN-to-LAN VPNs. The last exercise I practiced was to create a LAN-to-LAN VPN between two Pfsense firewalls, by using IPSEC protocols. I succeeded, with both firewalls in the same network. But I'm wondering if it's possible to do the same thing, with 2 Pfsense firewalls...
0
4633
by: adsilva | last post by:
A Windows Forms form does not have the event Unload, like VB6. What one acts like?
2
2351
muto222
by: muto222 | last post by:
How can i add a mobile payment intergratation into php mysql website.

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.