Improve company productivity with a Business Account.Sign Up

x
?
Solved

MySQL decimal field is rounding and shouldn't be

Posted on 2016-09-06
12
Medium Priority
?
82 Views
Last Modified: 2016-09-06
Hi there! I have a MySQL table that includes the following table column:

	percentDegree	decimal(3,1)	Not NULL	Default 0.0

Open in new window


When I try to run an update...

UPDATE tbl_degrees SET percentDegree = '76.9' WHERE dataDate = '2015'

Open in new window


...the 76.9 is entered in the table as 77.0.

I've seen other questions like this on here but it's usually a matter of people not having and decimal places defined or using the INT type. I've also seen a comment that "you can use FLOAT, but that comes with its own problems" but can't seem to find what those problems would be. Also, isn't this exactly the data type you would use decimals for?

Thanks!
0
Comment
Question by:SiobhanElara
  • 5
  • 4
  • 2
  • +1
12 Comments
 
LVL 56

Expert Comment

by:Ryan Chong
ID: 41786176
what about:

UPDATE tbl_degrees SET percentDegree = 76.9 WHERE dataDate = '2015'

?
1
 
LVL 22

Expert Comment

by:Kim Walker
ID: 41786192
How are you viewing the value that's stored in the table? Are you querying the table or are you browsing the table in phpMyAdmin or a similar MySQL management utility?

If you're querying the table, it's possible that it's getting rounded somehow before it's displayed.
0
 
LVL 56

Expert Comment

by:Ryan Chong
ID: 41786193
>>the 76.9 is entered in the table as 77.0
I just did a test, both SET percentDegree = '76.9' or SET percentDegree = 76.9 are working fine. they didn't turn to 77.0

more towards a display issue for me?
0
Keep up with what's happening at Experts Exchange!

Sign up to receive Decoded, a new monthly digest with product updates, feature release info, continuing education opportunities, and more.

 
LVL 62

Expert Comment

by:Julian Hansen
ID: 41786255
Confirm both '76.9' and 76.9 on a decimal(3,1) works as expected.

Where are you seeing 77.0
0
 

Author Comment

by:SiobhanElara
ID: 41786270
It's both displaying that way and in the database that way; I'm also viewing the table through phpMyAdmin. Here's a screenshot of a query, the form, and what's in the database. (I'd entered 26.7 as seen in the query; the area under that is the result. This is a slightly different query than the original question, but all tables are having this problem.)

decimal-wonkyness.jpg
0
 
LVL 62

Expert Comment

by:Julian Hansen
ID: 41786291
And if you run this directly in PHPMyAdmin
UPDATE data_educational_attainment SET percentBachelor=26.7 WHERE countryID=0 AND dataDate='2016';

Open in new window

0
 

Author Comment

by:SiobhanElara
ID: 41786307
That works, as does double-clicking on the cell on phpMYAdmin table view and entering it there.
0
 
LVL 62

Expert Comment

by:Julian Hansen
ID: 41786316
The problem is then in how you are submitting it to the DB - what is running that query?
0
 

Author Comment

by:SiobhanElara
ID: 41786350
The ColdFusion code is as follows:

<cfquery datasource="#APPLICATION.ds#" result="bloop">
UPDATE #FORM.tableName#
SET #FORM.dataName# = <cfqueryparam value="#FORM[i]#" cfsqltype="cf_sql_decimal">
WHERE countyID = <cfqueryparam value="#countyID#" cfsqltype="cf_sql_integer">
</cfquery>

Open in new window


("Bloop" outputs the query shown in the screenshot above.)
0
 
LVL 62

Accepted Solution

by:
Julian Hansen earned 2000 total points
ID: 41786366
And if you do this
<cfquery datasource="#APPLICATION.ds#" result="bloop">
UPDATE #FORM.tableName#
SET #FORM.dataName# = <cfqueryparam value="#FORM[i]#" scale="1" cfsqltype="cf_sql_decimal">
WHERE countyID = <cfqueryparam value="#countyID#" cfsqltype="cf_sql_integer">
</cfquery>

Open in new window

I don't use ColdFusion but according to the docs - the omission of the scale parameter defaults the value to 0 decimal places.
0
 

Author Closing Comment

by:SiobhanElara
ID: 41786416
Holy crap, I hang my head in shame. Thank you for pointing out what I should have known all along!
0
 
LVL 62

Expert Comment

by:Julian Hansen
ID: 41786467
You are welcome.
0

Featured Post

Free Tool: IP Lookup

Get more info about an IP address or domain name, such as organization, abuse contacts and geolocation.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

It is possible to export the data of a SQL Table in SSMS and generate INSERT statements. It's neatly tucked away in the generate scripts option of a database.
Recursive SQL is one of the most fascinating and powerful and yet dangerous feature offered in many modern databases today using a Common Table Expression (CTE) first introduced in the ANSI SQL 99 standard. The first implementations of CTE began ap…
In this video, Percona Solution Engineer Dimitri Vanoverbeke discusses why you want to use at least three nodes in a database cluster. To discuss how Percona Consulting can help with your design and architecture needs for your database and infras…
With just a little bit of  SQL and VBA, many doors open to cool things like synchronize a list box to display data relevant to other information on a form.  If you have never written code or looked at an SQL statement before, no problem! ...  give i…

606 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question