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How to add an auto-incrementing primary key to an existing table, in PostgreSQL?
...of PostgreSQL
In old versions of PostgreSQL (prior to 8.x?) you had to do all the dirty work. The following sequence of commands should do the trick:
ALTER TABLE test1 ADD COLUMN id INTEGER;
CREATE SEQUENCE test_id_seq OWNED BY test1.id;
ALTER TABLE test ALTER COLUMN id SET DEFAULT nextval('...
What is the effect of encoding an image in base64?
...
Here's a really helpful overview of when to base64 encode and when not to by David Calhoun.
Basic answer = gzipped base64 encoded files will be roughly comparable in file size to standard binary (jpg/png). Gzip'd binary files will ha...
How do you push just a single Git branch (and no other branches)?
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By default git push updates all the remote branches. But you can configure git to update only the current branch to it's upstream.
git config push.default upstream
It means git will update only the current (checked out) branch when you do git push.
...
How to set gradle home while importing existing project in Android studio
... plugin (which contains a bundled version of gradle) should be already installed in where/you/installed/android-studio/plugins/gradle so you shouldn't need to manually download it. Depending on the version of Android Studio, that last directory may be where/you/installed/android-studio/gradle/gradl...
string.IsNullOrEmpty(string) vs. string.IsNullOrWhiteSpace(string)
...ite
space besides empty string.
The term “white space” includes all characters that are not visible on
screen. For example, space, line break, tab and empty string are white
space characters*.
Reference : Here
For performance, IsNullOrWhiteSpace is not ideal but is
good. The ...
How to use LocalBroadcastManager?
...ustom-event-name"));
}
// Our handler for received Intents. This will be called whenever an Intent
// with an action named "custom-event-name" is broadcasted.
private BroadcastReceiver mMessageReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {...
Why array implements IList?
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Because an array allows fast access by index, and IList/IList<T> is are the only collection interfaces that support this. So perhaps your real question is "Why is there no interface for constant collections with indexers?" And to that I...
Remove empty lines in text using Visual Studio
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^\s+$\n changed to ^\s*$\n allow for (no content) pure line feeds.
– Joe Johnston
Jan 6 '15 at 16:15
4
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How does autowiring work in Spring?
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First, and most important - all Spring beans are managed - they "live" inside a container, called "application context".
Second, each application has an entry point to that context. Web applications have a Servlet, JSF uses a el-resolver, etc. Also, th...
Difference between getAttribute() and getParameter()
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Generally, a parameter is a string value that is most commonly known for being sent from the client to the server (e.g. a form post) and retrieved from the servlet request. The frustrating exception to this is ServletContext init...