You are probably seeking:

    ActiveRecord::Base.connection.tables

and

    ActiveRecord::Base.connection.columns(&#39;projects&#39;).map(&amp;:name)

You should probably wrap them in shorter syntax inside your `.irbrc`.

I hope my late answer can be of some help.      
This will go to rails database console.   

    rails db

pretty print your query output   

    .headers on
    .mode columns
    (turn headers on and show database data in column mode )

Show the tables 

    .table

&#39;.help&#39; to see help.   
Or use SQL statements like &#39;Select * from cars&#39;


To get a list of all model classes, you can use `ActiveRecord::Base.subclasses` e.g.


    ActiveRecord::Base.subclasses.map { |cl| cl.name }
    ActiveRecord::Base.subclasses.find { |cl| cl.name == &quot;Foo&quot; }

You can use `rails dbconsole` to view the database that your rails application is using. It&#39;s alternative answer `rails db`. Both commands will direct you the command line interface and will allow you to use that database query syntax.

Run this: 

    Rails.application.eager_load! 

Then

    ActiveRecord::Base.descendants

To return a list of models/tables

Its a start, it can list:

    models = Dir.new(&quot;#{RAILS_ROOT}/app/models&quot;).entries


Looking some more...

In the last weeks I&#39;ve seen some guys using really long names for a Method or Class (50 characters), this is usually under the premise that it improves readability, my opinion is that a long name like this is an indicator that we are trying to do a lot or too much in a method class if we need such a long name, however I wanted to know what do you guys think about it.

An Example is: 

    getNumberOfSkinCareEligibleItemsWithinTransaction

When is a Java method name too long?

How can I format numbers using a comma separator every three digits using jQuery?

For example:

&lt;!-- language: none --&gt;

    ╔═══════════╦═════════════╗
    ║   Input   ║   Output    ║
    ╠═══════════╬═════════════╣
    ║       298 ║         298 ║
    ║      2984 ║       2,984 ║
    ║ 297312984 ║ 297,312,984 ║
    ╚═══════════╩═════════════╝

Add comma to numbers every three digits

I was wondering if you could list/examine what databases/objects are available to you in the Rails console. I know you can see them using other tools, I am just curious.
Thanks.

Rails: How to list database tables/objects using the Rails console?

<p>I was wondering if you could list/examine what databases/objects are available to you in the Rails console. I know you can see them using other tools, I am just curious.
Thanks.</p>


I&#39;m looking to send raw post data (e.g. unparamaterized JSON) to one of my controllers for testing:

    class LegacyOrderUpdateControllerTest &lt; ActionController::TestCase
      test &quot;sending json&quot; do
        post :index, &#39;{&quot;foo&quot;:&quot;bar&quot;, &quot;bool&quot;:true}&#39;
      end
    end

but this gives me a &lt;code&gt;NoMethodError: undefined method `symbolize_keys&#39; for #&amp;lt;String:0x00000102cb6080&amp;gt;&lt;/code&gt; error.

What is the correct way to send raw post data in `ActionController::TestCase`?

Here is some controller code:

    def index
      post_data = request.body.read
      req = JSON.parse(post_data)
    end
    


How to send raw post data in a Rails functional test?

I am using link_to img tag like following

    &lt;%= link_to image_tag(&quot;Search.png&quot;, :border=&gt;0, :class =&gt; &#39;dock-item&#39;), 
    :action =&gt; &#39;search&#39;, :controller =&gt; &#39;pages&#39;%&gt;&lt;span&gt;Search&lt;/span&gt;&lt;/a&gt;


Which results in following html

    &lt;a href=&quot;/pages/search&quot;&gt;&lt;img alt=&quot;Search&quot; border=&quot;0&quot; class=&quot;dock-item&quot; 
    src=&quot;/images/Search.png?1264132800&quot; /&gt;&lt;/a&gt;&lt;span&gt;Search&lt;/span&gt;&lt;/a&gt; 

I want the class=&quot;dock-item&quot; to go to the `&lt;a&gt;` tag instead of the img tag. 

How can i change this?

**Update:**

    &lt;%= link_to image_tag(&quot;Search.png&quot;, :border=&gt;0), :action =&gt; &#39;search&#39;, 
    :controller =&gt; &#39;pages&#39;, :class =&gt; &#39;dock-item&#39; %&gt;

results in

    &lt;a href=&quot;/pages/search?class=dock-item&quot;&gt;&lt;img alt=&quot;Search&quot; border=&quot;0&quot; 
    src=&quot;/images/Search.png?1264132800&quot; /&gt;&lt;/a&gt; 



Rails: link_to image tag. how to add class to a tag

Rails has a `has_one :through` association that helps set up a one-to-one association with a third model by going through a second model. What is the real use of that besides making a shortcut association, that would otherwise be an extra step away.

Taking this example from the Rails [guide][1]:

    class Supplier &lt; ActiveRecord::Base
      has_one :account
      has_one :account_history, :through =&gt; :account
    end
    
    class Account &lt; ActiveRecord::Base
      belongs_to :supplier
      has_one :account_history
    end
    
    class AccountHistory &lt; ActiveRecord::Base
      belongs_to :account
    end

might allow us to do something like:

    supplier.account_history

which would otherwise be reached as:

    supplier.account.history

If it&#39;s only for simpler access then technically there could be a one-to-one association that connects a model with some nth model going through n-1 models for easier access. Is there anything else to it that I am missing besides the shortcut? 

  [1]: http://guides.rubyonrails.org/association_basics.html

Rails has_one :through association

Running &#39;`sudo gem list --local`&#39; and &#39;`gem list --local`&#39; give me differing results. My gem path is set to my home folder and only contains the gems from &#39;`gem list --local`&#39;.

It&#39;s probably not good to have gems installed in different directories on my computer, so should I have the gem path set differently, and should I always use `sudo` when installing something?

    my ~/.profile
    export PATH=/opt/local/bin:/opt/local/sbin:$PATH
    export PATH=&quot;/usr/local/bin:/usr/local/sbin:/usr/local/mysql/bin:$PATH&quot;

~/.bash_profile is empty.


&#39;sudo gem install&#39; or &#39;gem install&#39; and gem locations

I&#39;m starting a hobby (non-revenue) project using Ruby on Rails.  I&#39;ve done a fair amount of development in Rails using Postgresql, and I can make a pretty good imitation of normalized schema.  However, Mongrodb looks shiny and new.  What better for trying out something new than a hobby project?

Think back to when you started using Mongodb.  What techniques did you learn later that made you say, &quot;If only I knew that when I started!&quot;  What plug-ins did you discover that you would have used right from the start, if only you had known?  What references would you like to have had bookmarked?

Mongodb: What to know before using?

I am building a unit test in C# with NUnit, and I&#39;d like to test that the main program actually outputs the right output depending on the command line arguments.

Is there a way from an NUnit test method that calls `Program.Main(...)` to grab everything written to [`Console.Out`](https://docs.microsoft.com/en-us/dotnet/api/system.console.out) and [`Console.Error`](https://docs.microsoft.com/en-us/dotnet/api/system.console.error) so that I can verify against it?

Grabbing the output sent to Console.Out from within a unit test?

I have a Qt application, and when I run this application, there is a console opening behind it. In development it is nice because i see debug outputs on the console, but when I want to give this executable to the customer there should be no console window.
how do I hide it?

(I am using Visual Studio 2008)

Hide console of Windows Application

I want to print something in console, so that I can debug it.  But for some reason, nothing prints in my Android application.  

How do I debug then?


    public class HelloWebview extends Activity {
    	WebView webview;	
    	private static final String LOG_TAG = &quot;WebViewDemo&quot;;
    	private class HelloWebViewClient extends WebViewClient {
    	    @Override
    	    public boolean shouldOverrideUrlLoading(WebView view, String url) {
    	        view.loadUrl(url);
    	        return true;
    	    }
    	}
    	
        /** Called when the activity is first created. */
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.main);
            webview = (WebView) findViewById(R.id.webview);
            webview.setWebViewClient(new HelloWebViewClient());
            webview.getSettings().setJavaScriptEnabled(true);
            webview.setWebChromeClient(new MyWebChromeClient());
            webview.loadUrl(&quot;http://example.com/&quot;);    
            System.out.println(&quot;I am here&quot;);
        }

Why doesn&#39;t &quot;System.out.println&quot; work in Android?

Running `xcodebuild` from the console will bring you very verbose output and I wasn&#39;t able to locate any options for limit its output in order to display only warnings and errors.

I&#39;m looking for a way to capture the `xcodebuild` output and filter it. It would prefer a Python solution that will work with pipes but I&#39;m open to other approaches as long they are command line based solutions.

Are any tools that are already able to do this?

How to filter the xcodebuild command line output?

How to disable [logging](http://docs.python.org/library/logging.html) on the standard error stream in Python? This does not work:

```python
import logging

logger = logging.getLogger()
logger.removeHandler(sys.stderr)
logger.warning(&#39;foobar&#39;)  # emits &#39;foobar&#39; on sys.stderr
```

Content Type	Original Author	Original Content on Stackoverflow
Question	rtfminc	View Question on Stackoverflow
Solution 1 - Ruby on-Rails	cwninja	View Answer on Stackoverflow
Solution 2 - Ruby on-Rails	hamster ham	View Answer on Stackoverflow
Solution 3 - Ruby on-Rails	DomQ	View Answer on Stackoverflow
Solution 4 - Ruby on-Rails	Ralf Rafael Frix	View Answer on Stackoverflow
Solution 5 - Ruby on-Rails	stevec	View Answer on Stackoverflow
Solution 6 - Ruby on-Rails	rtfminc	View Answer on Stackoverflow

Rails: How to list database tables/objects using the Rails console?

Ruby on-Rails Problem Overview

Ruby on-Rails Solutions

Solution 1 - Ruby on-Rails

Solution 2 - Ruby on-Rails

Solution 3 - Ruby on-Rails

Solution 4 - Ruby on-Rails

Solution 5 - Ruby on-Rails

Solution 6 - Ruby on-Rails

Add comma to numbers every three digits

When is a Java method name too long?

Attributions