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Difference between Key, Primary Key, Unique Key and Index in MySQL
... A primary key is a column, or a combination of columns, that can uniquely identify a row. It is a special case of unique key. A table can have at most one primary key, but more than one unique key. When you specify a unique key on a column, no two distinct rows in a table can have the same value.
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Backbone.View “el” confusion
...r want to see it do anything.
An example:
I have a view that creates individual items
window.ItemView = Backbone.View.extend({
tagName: "li", //this defaults to div if you don't declare it.
template: _.template("<p><%= someModelKey %></p>"),
events: {
//this...
Finding sum of elements in Swift array
...lection of elements down to a single value by recursively applying the provided closure". We give it 0 as the initial value, and then, essentially, the closure { $0 + $1 }. Of course, we can simplify that to a single plus sign, because that's how Swift rolls.
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How to align 3 divs (left/center/right) inside another div?
I want to have 3 divs aligned inside a container div, something like this:
18 Answers
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Check if option is selected with jQuery, if not select a default
...y what you want to accomplish, this bit of code worked for me.
<select id="mySelect" multiple="multiple">
<option value="1">First</option>
<option value="2">Second</option>
<option value="3">Third</option>
<option value="4">Fourth</option&g...
Refresh Fragment at reload
In an android application I'm loading data from a Db into a TableView inside a Fragment . But when I reload the Fragment it displays the previous data. Can I repopulate the Fragment with current data instead of previous data?
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Generate Java classes from .XSD files…?
... that I want the element to be arranged in XML output.
@XmlAttribute(name="id", ...) indicates that id is an attribute to root element.
@XmlElement(....) indicates that I want price and name to be element within Item.
My Item.java is ready. I can then go ahead and create JAXB script for marshaling...
Refreshing web page by WebDriver when waiting for specific condition
...d
driver.get("https://accounts.google.com/SignUp");
driver.findElement(By.id("firstname-placeholder")).sendKeys(Keys.F5);
Using navigate.refresh() method
driver.get("https://accounts.google.com/SignUp");
driver.navigate().refresh();
Using navigate.to() method
driver.get("https://accounts.goog...
Android Notification Sound
...otification to make a sound. It will vibrate and flash the light. The android documentation says to set a style which I've done with:
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How do I implement basic “Long Polling”?
...ly freeze up. This would better be done checking if the file contains a valid JSON response, and/or keeping a running total of requests-per-minute/second, and pausing appropriately.
If the page errors, it appends the error to the #messages div, waits 15 seconds and then tries again (identical to ho...