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Want to find records with no associated records in Rails
...).where( :friends => { :person_id => nil } )
For the hmt it's basically the same thing, you rely on the fact that a person with no friends will also have no contacts:
Person.includes(:contacts).where( :contacts => { :person_id => nil } )
Update
Got a question about has_one in the c...
How to calculate date difference in JavaScript?
... 24 hours, and any 'variation' in that due to Daylight Savings Time is actually a switch of timezones. If you don't distinguish between timezones already, trying to figure out a time difference is going to put you in a world of hurt, not least because the DST switchover 'repeats' time. Stay in one t...
MySQL connection not working: 2002 No such file or directory
...dPress. I have Apache and MySQL running, and the accounts and database are all set up. I tried to make a simple connection:
...
Eclipse interface icons very small on high resolution screen in Windows 8.1
...rious icons and buttons in the Eclipse (Kepler) interface are very, very small on a laptop with a 3200x1800px screen. The red error decoration that appears to indicate errors on files is difficult to see unless my nose a few cm from the screen.
...
Better to 'try' something and catch the exception or test if it's possible first to avoid an excepti
...est option when the index is probably in the list and the IndexError is usually not raised. This way you avoid the need for an extra lookup by if index < len(my_list).
Python encourages the use of exceptions, which you handle is a phrase from Dive Into Python. Your example not only handles the e...
Is proprietary code legally safe on bitbucket or github? [closed]
... yours. However, by setting your pages to be viewed publicly, you agree to allow others to view your Content. By setting your repositories to be viewed publicly, you agree to allow others to view and fork your repositories.
As noted in the BitBucket TOS you linked, BitBucket's parent company simil...
What does it mean when a CSS rule is grayed out in Chrome's element inspector?
... selected DOM node.
I guess, for the sake of completeness, dev tools shows all the rules from that set, whether they are applied or not.
In the case where a rule is applied to the currently selected element due to inheritance (i.e. the rule was applied to an ancestor, and the selected element inher...
How do I get java logging output to appear on a single line?
....ZipUtil unzip: Failed to load: foo.zip
2) Putting it to IDEs
IDEs typically let you set system properties for a project.
E.g. in NetBeans, instead of adding -D...=... somewhere, add the property in the action dialog, in a form of java.util.logging.SimpleFormatter.format=%1$tY-%1$tm-... - without...
How to round a number to n decimal places in Java
...ues into account. Floating point values have a binary representation internally. That means that a value like 2.7735 does not actually have that exact value internally. It can be slightly larger or slightly smaller. If the internal value is slightly smaller, then it will not round up to 2.7740. To r...
项目管理实践【六】自动同步数据库【Using Visual Studio with Source Cont...
... Visual Studio with Source Control System to synchronize database automatically】在上一篇项目管理实践【五】自动编译和发布网站中，我们讲解了如何使用MSBuild+Robocopy+WebDeployment来自动编译和部署网站，今天，我们来 在上一篇项目管理实践【...