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Should each and every table have a primary key?
... creates a primary key if you didn't specify it explicitly, thus making an extra column you don't have access to.
Note that a primary key can be composite.
If you have a many-to-many link table, you create the primary key on all fields involved in the link. Thus you ensure that you don't have two ...
Add EBS to Ubuntu EC2 Instance
...! I was totally confused by the /mnt directory and wrongly assumed that my extra EBS volume (/dev/xvdf) that I told AWS to attach at instance creation was already mounted. Also, the mapping between what AWS shows (/dev/sdf) and (/dev/xvdf) that exists on ubuntu tripped me up.
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Remove padding or margins from Google Charts
...ifferent styles. For instance, here is a version that removes most of the extra blank space by setting the chartArea.width to 100% and chartArea.height to 80% and moving the legend.position to bottom:
// Set chart options
var options = {'title': 'How Much Pizza I Ate Last Night',
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Comparing two NumPy arrays for equality, element-wise
...two NumPy arrays for equality (where equality is defined as: A = B iff for all indices i: A[i] == B[i] )?
6 Answers
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Check if SQL Connection is Open or Closed
...xactly - use the SqlConnectionState enum as an enum and not turn it into a string.....
– marc_s
Aug 4 '11 at 15:19
4
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What are some better ways to avoid the do-while(0); hack in C++?
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Try to extract the code into a separate function (or perhaps more than one). Then return from the function if the check fails.
If it's too tightly coupled with the surrounding code to do that, and you can't find a way to reduce the ...
Enabling HTTPS on express.js
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All is written here: github.com/visionmedia/express/wiki/Migrating-from-2.x-to-3.x Paragraph Application function
– codename-
Jul 31 '12 at 16:50
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Shards and replicas in Elasticsearch
...e need to create an index.
When you create an index (an index is automatically created when you index the first document as well) you can define how many shards it will be composed of. If you don't specify a number it will have the default number of shards: 5 primaries. What does it mean?
It mean...
html5 - canvas element - Multiple layers
...element.
https://github.com/federicojacobi/layeredCanvas
I intend to add extra capabilities, but for now it will do.
You can do multiple functions and call them in order to "fake" layers.
share
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Unit testing of private methods [duplicate]
...X has a lot of code in the private member functions then it might be worth extracting a new class Y which is used by the implementation of class X. This new class Y can then be tested through its public interface, without exposing its use to the clients of class X.
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