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postgresql - add boolean column to table set default
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Note that if your table is big this can take a long time and lock the table for the entire time. It's faster to split it into steps: add the column without a default with ALTER TABLE users ADD COLUMN priv_user BOOLEAN;, then UPDATE users SET priv_user = 'f'; and finally if you need...
Safely limiting Ansible playbooks to a single machine?
...all group of computers. Currently, I have my playbooks set to hosts: all and my hosts file is just a single group with all machines listed:
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How can I view the source code for a function?
...S4 method dispatch system
The S4 system is a newer method dispatch system and is an alternative to the S3 system. Here is an example of an S4 function:
> library(Matrix)
Loading required package: lattice
> chol2inv
standardGeneric for "chol2inv" defined from package "base"
function (x, ...)...
Programmatically align a toolbar on top of the iPhone keyboard
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As of iOS 3.2 there's a new way to achieve this effect:
UITextFields and UITextViews have an inputAccessoryView property, which you can set to any view, that is automatically displayed above and animated with the keyboard.
Note that the view you use should neither be in the view hierarchy els...
How can I count the occurrences of a list item?
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Use Counter if you are using Python 2.7 or 3.x and you want the number of occurrences for each element:
>>> from collections import Counter
>>> z = ['blue', 'red', 'blue', 'yellow', 'blue', 'red']
>>> Counter(z)
Counter({'blue': 3, 'red': 2, 'ye...
Html List tag not working in android textview. what can i do?
Html List tag not working in android TextView. This is my string content:
15 Answers
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How to remove gaps between subplots in matplotlib?
... gaps between the subplots. How do I remove the gaps between the subplots and make the image a tight grid?
5 Answers
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Domain Driven Design: Domain Service, Application Service
Can someone explain the difference between domain and application services by providing some examples? And, if a service is a domain service, would I put the actual implementation of this service within the domain assembly and if so, would I also inject repositories into that domain service? Some in...
When should i use npm with “-g” flag and why?
...g npm for js package management recently. Although I do have a fair understanding of package management in different enivronments(lets say using apt, rvm/gem, pythonbrew/virtualenv/pip), I don't quite understand how npm fully fits in.
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How to customize the back button on ActionBar
I have been able to customize the action bar's background, logo image and text color using suggestions from these:
Android: How to change the ActionBar "Home" Icon to be something other than the app icon?
ActionBar text color
ActionBar background image
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