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Rails :include vs. :joins
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.joins will just joins the tables and brings selected fields in return. if you call associations on joins query result, it will fire database queries again
:includes will eager load the included associations and add them in memory. :includes loads all the included tabl...
How to use Servlets and Ajax?
...and execute the following function with Ajax response JSON...
var $select = $("#someselect"); // Locate HTML DOM element with ID "someselect".
$select.find("option").remove(); // Find all child elements with tag name "option" and rem...
select and update database record with a single queryset
How do I run an update and select statements on the same queryset rather than having to do two queries:
- one to select the object
- and one to update the object
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What do querySelectorAll and getElementsBy* methods return?
...sByClassName (and similar functions like getElementsByTagName and querySelectorAll ) work the same as getElementById or do they return an array of elements?
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Where does Console.WriteLine go in ASP.NET?
...ass DebugTextWriter : System.IO.TextWriter {
public override void Write(char[] buffer, int index, int count) {
System.Diagnostics.Debug.Write(new String(buffer, index, count));
}
public override void Write(string value) {
System.Diagnostics.Debug.Write(value);
}
public...
How to get the data-id attribute?
...e info here">My Awesome Div</div>
JS
var myDiv = document.querySelector('#my-div');
myDiv.dataset.info // "some info here"
myDiv.dataset.otherInfo // "more info here"
Demo: http://html5demos.com/dataset
Full browser support list: http://caniuse.com/#feat=dataset
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Missing Push Notification Entitlement
...from the answer given by @Vaiden, in Xcode 8 you can resolve this issue by selecting the target and clicking the "Fix issue". Of course, you'll still need to set up push notifications in the Apple Developer portal (you can simplify the process a little by using the new "Automatically manage signing"...
String vs. StringBuilder
... .NET are immutable). It works by keeping an internal buffer, an array of char. Calling Append() or AppendLine() adds the string to the empty space at the end of the char array; if the array is too small, it creates a new, larger array, and copies the buffer there. So in the example above, String...
MySQL - SELECT WHERE field IN (subquery) - Extremely slow why?
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Rewrite the query into this
SELECT st1.*, st2.relevant_field FROM sometable st1
INNER JOIN sometable st2 ON (st1.relevant_field = st2.relevant_field)
GROUP BY st1.id /* list a unique sometable field here*/
HAVING COUNT(*) > 1
I think st2.relevant_...
What is the Java string pool and how is “s” different from new String(“s”)? [duplicate]
...: String s = GlobalStringObjectCache.get("hello");
– Charles Goodwin
May 30 '16 at 12:07
7
Copy-p...