This behavior was part of [RFC 1808][1] (Section 4) which is about 16 years old, so every major browser should (and does) support this.

Sadly, there&#39;s [a bug with IE7 and -8][2] that will make them download the resources twice if a protocol-relative URL is used on a `link` or `@import` - which shouldn&#39;t be a big problem, but is ugly and should be kept in mind.


  [1]: https://www.rfc-editor.org/rfc/rfc1808#section-4
  [2]: http://paulirish.com/2010/the-protocol-relative-url/

If you are developing on a local machine there&#39;s possibility it will fail with `src=&quot;file://host.com/filename&quot;.`

In this situation you need to specify scheme explicitly: `http://host.com/filename` or `https://host.com/filename`.

I have an application that uses a SQLite database and everything works the way it should. I&#39;m now in the process of adding new functionalities that require a second SQLite database, but I&#39;m having a hard time figuring out how to join tables from the different databases.

If someone can help me out with this one, I&#39;d really appreciate it!

&lt;b&gt;Edit: &lt;/b&gt; See [this question][1] for an example case you can adapt to your language when you attach databases as mentioned in the accepted answer.


  [1]: https://stackoverflow.com/questions/4865684/blackberry-sqlite-attach-one-sqlite-database-to-another

SQLite - How do you join tables from different databases?

I have 2 tables. `tbl_names` and `tbl_section` which has both the `id` field in them. How do I go about selecting the `id` field, because I always get this error:

    1052: Column &#39;id&#39; in field list is ambiguous

Here&#39;s my query:

    SELECT id, name, section
      FROM tbl_names, tbl_section 
     WHERE tbl_names.id = tbl_section.id

I could just select all the fields and avoid the error. But that would be a waste in performance. What should I do?

1052: Column &#39;id&#39; in field list is ambiguous

I&#39;ve recently seen a few links used without a protocol. It didn&#39;t seem too difficult to understand - I think it&#39;s a great idea and pretty intuitive.

For those of you unaware, using a URL like `//example.com/script.js` will point to either `http://example.com/script.js` or `https://example.com/script.js` depending on whether or not the URL originates from a **http** or **https** URL. Including http scripts or images from a https page can be a security concern, for example, so this solves that without the need for protocol detection in your code.

My question is, what sort of browser/OS support is there for it? Is it safe to use in production? It would certainly make things a bit easier.

Simple example and test:
http://codetester.org/916c6916

EDIT:
Just a follow up that I&#39;ve been using this for my company&#39;s ad server in production for many things without issue for a couple years now.

Browser support for URLs beginning with double slash

I've recently seen a few links used without a protocol. It didn't seem too difficult to understand - I think it's a great idea and pretty intuitive.
For those of you unaware, using a URL like <code>//example.com/script.js</code> will point to either <code>http://example.com/script.js</code> or <code>https://example.com/script.js</code> depending on whether or not the URL originates from a http or https URL. Including http scripts or images from a https page can be a security concern, for example, so this solves that without the need for protocol detection in your code.
My question is, what sort of browser/OS support is there for it? Is it safe to use in production? It would certainly make things a bit easier.
Simple example and test:
<a href="http://codetester.org/916c6916" target="_blank" rel="noopener noreferrer">http://codetester.org/916c6916</a>
EDIT:
Just a follow up that I've been using this for my company's ad server in production for many things without issue for a couple years now.

Using Javascript, I want to generate a link to a page. The parameters to the page are in a Javascript array that I serialize in JSON.

So I would like to generate a URL like that :

    http://example.com/?data=&quot;MY_JSON_ARRAY_HERE&quot;

**How do I need to escape my JSON string (array serialized) to include it as a parameter in a URL ?**

If there&#39;s a solution using JQuery I&#39;d love it.

*Note: Yes, the parameters to the page need to be in an array because there are a lot of them. I think I&#39;ll use bit.ly to shorten the links afterwards.*

How to escape a JSON string to have it in a URL?

I&#39;m making the switch from CodeIgniter to Symfony 2. 
Can someone please give me an example of how to: 

 - Get the base url (the url without the route specific parts)
 - Globally pass this variable to the twig bundle so I can use it in every template.

Getting the base url of the website and globally passing it to twig in Symfony 2

&gt; **Possible Duplicate:**  
&gt; [What is the best regular expression to check if a string is a valid URL?](https://stackoverflow.com/questions/161738/what-is-the-best-regular-expression-to-check-if-a-string-is-a-valid-url)  

&lt;!-- End of automatically inserted text --&gt;

Considering a string as follows:

    string = &quot;&lt;p&gt;Hello World&lt;/p&gt;&lt;a href=&quot;http://example.com&quot;&gt;More Examples&lt;/a&gt;&lt;a href=&quot;http://example2.com&quot;&gt;Even More Examples&lt;/a&gt;&quot;

How could I, with Python, extract the urls, inside the anchor tag&#39;s href? Something like:

    &gt;&gt;&gt; url = getURLs(string)
    &gt;&gt;&gt; url
    [&#39;http://example.com&#39;, &#39;http://example2.com&#39;]

Thanks!

Regex to extract URLs from href attribute in HTML with Python

I have getting dynamic text from a web service and showing the same in a TextView. Sometimes the TextView has url like `&lt;a href=&quot;http://hello.com&quot;&gt;hello&lt;/a&gt;`. I have set the text using the following code.


    textView.setText(Html.fromHtml(sampletext));

And also set `android:autoLink=&quot;web&quot;` in the corresponding xml of that contains the `TextView`. Now the link is showing properly with blue color and underline, but I found the its just a dead link. Nothing is happening if we try to click it. What I have to do to make the link active?

Android active link of url in TextView

How do I get an InputStream from a URL?

for example, I want to take the file at the url `wwww.somewebsite.com/a.txt` and read it as an InputStream in Java, through a servlet.

I&#39;ve tried

    InputStream is = new FileInputStream(&quot;wwww.somewebsite.com/a.txt&quot;);

but what I got was an error:

    java.io.FileNotFoundException


InputStream from a URL

Basically the question is in the title.

Many people have had the question stackoverflow of how to create a data URI and problems therein.

My question is *why use data URI?*

What are the advantages to doing:

    &lt;img src=&quot;data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUA
    AAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO
    9TXL0Y4OHwAAAABJRU5ErkJggg==&quot; alt=&quot;Red dot&quot; /&gt;

Over doing:

    &lt;img src=&quot;dot.png&quot; alt=&quot;Red dot&quot; /&gt;


I understand one has less overhead on the server side (maybe), but what are the **real** advantages/disadvantages to using *data URI*?

Why use data URI scheme?

Is it possible to hide the Javascript code from the html of a webpage, when the source code is viewed through the browsers View Source feature? 

I know it is possible to obfuscate the code, but I would prefer it being *hidden* from the view source feature.

How do I hide javascript code in a webpage?

Is there a reliable way to get a timezone from client browser? I saw the following links but I want a more robust solution. 

[Auto detect a time zone with JavaScript](http://www.onlineaspect.com/2007/06/08/auto-detect-a-time-zone-with-javascript/)

[Timezone detection in JavaScript](https://bitbucket.org/pellepim/jstimezonedetect/wiki/Home)



get client time zone from browser

If you go to a page a and scroll around then refresh the page will refresh at the spot where you left it. This is great, however this also occurs on pages where there is a anchor location in the url. An example would be if you clicked on a link `http://example.com/post/244#comment5` and refreshed the page after looking around you would not be at the anchor and the page jumps around. Is there any way to prevent this with javascript? So that no-matter-what you would always navigate to the anchor.

Prevent automatic browser scroll on refresh

I&#39;m building a web app and wanting to disable transitions effects on Android devices under version 3.0. 

Is there anyway to pick up the Android version number by Javascript in the browser? If so how?


Pick up the Android version in the browser by Javascript

Since [`element.classList`][1] is not supported in IE 9 and Safari-5, what&#39;s an alternative cross-browser solution?

[No-frameworks][2] please.

Solution **must** work in at least **IE 9**, **Safari 5**, FireFox 4, Opera 11.5, and Chrome.

Related posts (but does not contain solution):

 1. https://stackoverflow.com/questions/2170878/how-to-add-and-remove-css-class

 2. https://stackoverflow.com/questions/5084182/add-and-remove-a-class-with-animation

 3. https://stackoverflow.com/questions/3066692/add-remove-class


  [1]: https://developer.mozilla.org/en-US/docs/Web/API/Element.classList#Browser_compatibility
  [2]: http://vanilla-js.com/

How to add/remove a class in JavaScript?

**Where can I find a browser&#39;s default CSS for HTML elements?**

Many HTML elements come with some default CSS properties which can sometimes result in unknown/unwanted behaviour. For example Input boxes are displayed differently in different browsers. I&#39;m looking for a place that covers the new CSS3 properties and the new HTML5 elements.

I&#39;ve seen in other (much older) questions (such as https://stackoverflow.com/questions/32875/browsers-default-css) answers that suggest a solution of CSS reset. This solution is sometimes not wanted, often I would actually like to keep some of the basic properties (such as the highlighting of input boxes in Chrome). In other words: *I don&#39;t want to get rid of things just because I don&#39;t know what they do*.

So, **Is there a site that can give me all this information (or perhaps most)?**



Browsers&#39; default CSS for HTML elements

There`s some extra space under textarea tag. From 1 to 4 pixels in different browsers. The markup is very simple:

    &lt;!DOCTYPE html PUBLIC &quot;-//W3C//DTD XHTML 1.0 Strict//EN&quot; &quot;http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd&quot;&gt;
    
    &lt;html&gt;
        &lt;head&gt;
            &lt;style&gt;
                body {
    	            margin: 0;
    	            padding: 0;
                }
                .main {
    	            background-color: red;
                }
                textarea {
    	            background-color: gray;
    	            resize: none;
    	            margin: 0;
    	            border: 0 none;
    	            padding: 10px;
    	            height: 50px;
    	            overflow: hidden;
                }
            &lt;/style&gt;
        &lt;/head&gt;
        &lt;body&gt;
            &lt;div class=&quot;main&quot;&gt;
                &lt;textarea&gt;&lt;/textarea&gt;
            &lt;/div&gt;
        &lt;/body&gt;
    &lt;/html&gt;


Here&#39;s how it is rendered in browsers:

![Screenshot][1]

Why is this happening? How to remove this extra space?


  [1]: http://i.stack.imgur.com/66R1y.jpg

Extra space under textarea, differs along browsers

I have read a bit on this, but I can&#39;t seem to find anything solid about how different browsers treat things.

What&#39;s the difference between disabled=&quot;disabled&quot; and readonly=&quot;readonly&quot; for HTML form input fields?

`Highcharts` chart option `backgroundColor:&#39;transparent&#39;` showing black on `IE 8`

    histogram = new Highcharts.Chart({
                chart: { renderTo: &#39;histogram&#39;, defaultSeriesType: &#39;bar&#39;,
                         backgroundColor:&#39;transparent&#39;
                }

This works fine on `I.E 9` and others but fails on I.E 8 and Safari anyone has any idea why ?

Content Type	Original Author	Original Content on Stackoverflow
Question	dtbarne	View Question on Stackoverflow
Solution 1 - Url	oezi	View Answer on Stackoverflow
Solution 2 - Url	Matas Vaitkevicius	View Answer on Stackoverflow

Browser support for URLs beginning with double slash

Url Problem Overview

Url Solutions

Solution 1 - Url

Solution 2 - Url

1052: Column 'id' in field list is ambiguous

SQLite - How do you join tables from different databases?

Attributions