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How to convert a Django QuerySet to a list
...
By the use of slice operator with step parameter which would cause evaluation of the queryset and create a list.
list_of_answers = answers[::1]
or initially you could have done:
answers = Answer.objects.filter(id__in=[ans...
When to use setAttribute vs .attribute= in JavaScript?
...ively case insensitive.
Example Usage:
var div = document.getElementsByTagName('div')[0];
//you can look up specific attributes
var classAttr = div.attributes.getNamedItem('CLASS');
document.write('attributes.getNamedItem() Name: ' + classAttr.name + ' Value: ' + classAttr.value + '<br...
How to put Google Maps V2 on a Fragment using ViewPager
...
By using this code we can setup MapView anywhere, inside any ViewPager or Fragment or Activity.
In the latest update of Google for Maps, only MapView is supported for fragments. MapFragment & SupportMapFragment doesn't w...
Why this line xmlns:android=“http://schemas.android.com/apk/res/android” must be the first in the la
... the android
namespace.
Its used like this because this is a design choice by google to
handle the errors at compile time.
Also suppose we write our own textview widget with different
features compared to android textview, android namespace helps to
distinguish between our custom textview widget and...
MySQL, update multiple tables with one query
... also need to reduce that the total number of books available in our stock by the same number in Books table.
UPDATE Books, Orders
SET Orders.Quantity = Orders.Quantity + 2,
Books.InStock = Books.InStock - 2
WHERE
Books.BookID = Orders.BookID
AND Orders.OrderID = 1002;
...
Using querySelectorAll to retrieve direct children
...upported on [pre-Chrominum] versions of Edge or IE, but has been supported by Safari for a few years already. Using that, your code could become:
let myDiv = getElementById("myDiv");
myDiv.querySelectorAll(":scope > .foo");
Note that in some cases you can also skip .querySelectorAll and use o...
How to link to a named anchor in Multimarkdown?
..."></a> where you want to link to and refer to it on the same page by [link text](#abcd).
(This uses name= and not id=, for reasons explained in this answer.)
Remote references can use [link text](http://...#abcd) of course.
This works like a dream, provided you have control over the sour...
How to remove array element in mongodb?
...
@ShubhamA. by default .update() updates a single document. To update multiple documents use { multi: true } option. See db.collection.update docs for details.
– Leonid Beschastny
Sep 6 '17 at 16:50...
How to set auto increment primary key in PostgreSQL?
...now!
(3 rows)
The two rows have keys that start at 1 and are incremented by 1, as defined by the sequence.
Bonus Elite ProTip:
Programmers hate typing, and typing out the nextval('splog_adfarm_seq') is annoying. You can type DEFAULT for that parameter instead, like this:
insert into splog_adfa...
How do I add indices to MySQL tables?
...s can be added: when you define a primary key, MySQL will take it as index by default.
Explanation
Primary key as index
Consider you have a tbl_student table and you want student_id as primary key:
ALTER TABLE `tbl_student` ADD PRIMARY KEY (`student_id`)
Above statement adds a primary key, whi...