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Two single-column indexes vs one two-column index in MySQL?
...ses also more disk space.
When choosing the indexes, you also need to consider the effect on inserting, deleting and updating. More indexes = slower updates.
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How do I check how many options there are in a dropdown menu?
...tList > option').length;
This assumes your <select> list has an ID of mySelectList.
http://api.jquery.com/length/
http://api.jquery.com/children/
http://api.jquery.com/child-selector/
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How to implement the Android ActionBar back button?
...etty code:
public class ServicesViewActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// etc...
getActionBar().setDisplayHomeAsUpEnabled(true);
}
@Override
public boolean onOpti...
How can I do width = 100% - 100px in CSS?
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Modern browsers now support the:
width: calc(100% - 100px);
To see the list of supported browser versions checkout: Can I use calc() as CSS unit value?
There is a jQuery fallback: css width: calc(100% -100px); alternative using jquery
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C# Lazy Loaded Automatic Properties
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Here's my implementation of a solve to your problem. Basically the idea is a property that will be set by a function at first access and subsequent accesses will yield the same return value as the first.
public class LazyProperty<T>
{
bool _initialized = false;
T _result;...
How to print HTML content on click of a button, but not the page? [duplicate]
...me across another elegant solution for this:
Place your printable part inside a div with an id like this:
<div id="printableArea">
<h1>Print me</h1>
</div>
<input type="button" onclick="printDiv('printableArea')" value="print a div!" />
Now let's create a rea...
ActiveRecord: List columns in table from console
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Great! Using Model.columns provides all the information for a table through ActiveRecord. Crucially for me it was the only and easiest way to gain confidence in what my primary key really was at the database level.
– nibbex
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What's the difference between a POST and a PUT HTTP REQUEST?
They both seem to be sending data to the server inside the body, so what makes them different?
17 Answers
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Get names of all keys in the collection
...resulting collection so as to find all the keys:
db[mr.result].distinct("_id")
["foo", "bar", "baz", "_id", ...]
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How to change the text on the action bar
...world App");
getSupportActionBar().setTitle("Hello world App"); // provide compatibility to all the versions
=> Customizing Action Bar,
For example:
@Override
public void setActionBar(String heading) {
// TODO Auto-generated method stub
com.actionbarsherlock.app.ActionBar actionB...