December 23, 2014

A Small Gift for New Graduates: 4 Suggestions for Job Hunting


It’s almost Christmas. We just graduated from school in December and now cheer with our family in a cozy house this week of Christmas, but at the same time, we feel so nervous and anxious about the new year of job hunting.


I am not a recruiter, or a manager with many years of experience. I am one of the thousands of new graduate students with zero years of full time working experience.
After three months of job hunting after my graduation from the University of Cincinnati, I landed my job at Amazon.com as a BI Engineer at the beginning of November. I would like to share my story of job hunting here with you.

Two main misleading features of Google Maps on iPhone


For years I have been a big fan of Google and fascinated about the awesome features of Google Maps. The most recent version of Google Map on iOS looks very similar with the new Google Map on Lollipop, but not entirely. At the same time, I am confused about direction by two new features on the map. 


October 23, 2014

How to embed the Tableau dashboard on Weebly?

Recently a few friends asked me question about how to embed the Tableau dashboard on your weebly, your page, or your squarespace which provided HTML coding features. 

Trust me, Tableau did not ask you for any coding skills when you want to put your awesome dashboard on your site. What you need to do is just "copy and paste". So let's get started. 


Step 1: Upload your files on Tableau Public

Upload it directly from your Tableau Desktop. Server --> Tableau Public --> Save to Web










After you finished the step shown in the image above, a window will pop up. 














Here it asked for your Tableau Public account. Your Tableau account is separated from your Tableau Public account, which means that you have to register a Tableau Public, sepearted from Tableau account to upload your files. Don't get stuck in this step when the window constantly reminds you of an error on your username and password. 

After you upload your dashboard and related files to Tableau Public, a window will pop up and congratulate that you successfully published your dashboard on your Tableau Public account. 



Step 2: Find the link.

Option 1 - Click "Share" button --> Choose "Embed" --> Copy the codes 




















Option 2: When you want to embed other people's dashboard

If you have other people's dashboard on your browser, you can see the small icon as the image below (Not the "share" button as the last option). 
Remark: "Share" button is only available when you own the dashboard and open it on your Tableau desktop or Tableau Public account. 

Action: Click that small icon. 



























Then you will see a small window pop up like the image below:

























Step 3: Find the "Embed Codes" Option on Weebly



























Step 4: Paste your codes

Click the box of "Embed code" --> Paste your codes. 















It's easy, right? 


More Info: 

If you would like to know more about this, check out Tableau official tutorial on their page here. Tableau did not use Weebly as an example on their tutorial, but I believe it would be helpful for you to check out the tutorial. : )

If your browser cannot open the link, copay and paste the link on a new tab: http://www.tableausoftware.com/public/how-it-works. 


October 1, 2014

Awesome online free sources for you to start learning SQL and prepare for the Oracle Certification Exam

According to Oracle website (Original link is here), in order to get the Oracle Database Administrator Certified Associate Level, candidates have to pass one of the three exams:
- Oracle Database 11g: SQL Fundamentals I (Exam #: 1Z0-051) 
- Oracle Database 12c: SQL Fundamentals (Exam #: 1Z0-061)
- Oracle Database SQL Expert (Exam #: 1Z0-047)
And after you pass one of the three exams listed above, you have to pass Oracle Database 11g: Administration I (Exam #: 1Z0-052) 

I chose Oracle Database 11g: SQL Fundamentals I (Exam #: 1Z0-051)  as my goal during the first step of getting the certification. If you chose the training provided by Oracle, it would cost you a lot of money. So I am going to introduce some websites to save you $3000. 

1. CBT Nuggets ( https://www.cbtnuggets.com/
This is the best site I found on Google after searching for half an hour. It asked you to put your credit card information when you open the 7-day free trail. Don't worry. I called the customer service to confirm that my card would not be charged. Another benefit is that after 7 days, if you forget to do anything with the website, it would not automatically charge your card. They have a 10-hours long tutorial for you to prepare the Oracle Database 11g: SQL Fundamental I (Exam#: 1Z0-051). 
Pros: 
- Free for 7 Days
- Video Format
- Give you clear goal of each episode 
- The course to prepare the exam explains the basic concepts of SQL very well which is absolutely the best tutorial for passing the exam. 
Cons: 
- If you don't have 7 days available for the course, you might have to subscribe their annual payment. 
- It does not give you specific questions to practice your SQL skills

2. SQL Course2 ( http://www.sqlcourse2.com/
This website provided advanced level SQL tutorial but unfortunately they did not provide video tutorials like CBT Nuggets.
Pros: 
It gives you specific questions to practice your SQL skills with answers attached. 
Cons:
It did not provide video tutorial for you to understand SQL. 

3. W3 School (http://www.w3schools.com/sql/default.asp
This site is designed for beginners of SQL. It does not provide enough materials for you to pass the exam and understand the basic concepts of SQL. However, if you just use basic commands or single row functions at work, this place is good enough for you. The best thing of this place is that you could try the SQL command directly on their website. They already store the tables that designed for you to practice on their site. You do not need to install MySQL on your computer. 
Pros:
Good for beginner
Practice your SQL and write your code directly on their website
You do not need to install SQL to runt the code on their site
Cons:
Not enough for you to pass the exam
It does not provide advanced level SQL (such as CASE, EXIST) 



September 30, 2014

Lessons I learned from SQL Interview

So today I had a technical interview with a company in Seattle. It was my first technical interview after two months of job hunting in the west coast. I am writing this posts to remember what I made a mistake in SQL as people usually say we learn lessons from mistakes and failure. 

First, About the rule that "GROUP BY function only allows you to SELECT two columns at a time". 
Remark: This does NOT include the new column you generate by using COUNT!!
Typical way you write a query with GROUP BY is like this:

SELECT Column1, Column 2 FROM TableName
GROUP BY Column1; 

HOWEVER, if you want to COUNT something else besides Column 1 and Column 2, you can write:

SELECT Column1, Column2, COUNT(Column3) 
FROM TableName
GROUP BY Column 1; 
SQL will not generate the errors when you put the third elements "COUNT(Column3) before "FROM TableName GROUP BY Column1" because "COUNT(Column3)" is not considered as the third column in the "GROUP BY". 

How about if you use JOIN to make it more complex. Then your query would be:
SELECT Table1.Column1, Table2.Column2, COUNT (Table2.Column3))
FROM Table1 JOIN Table 2 
ON Table1. Primarykey = Table2. Foreignkey
GROUP BY Column1; 

The reasons why you might better use Table1.Column1 instead of Column1 in this query when you have two tables is that the names of two columns in two tables might be the same. 

Second, About the data type of the date
Remember as the data type of the date is VARCHAR which means characters, you cannot use WHERE Date = 2004 to select the years. Assuming that the date in the table would be like "01-JAN-2004". You should write the query:
SELECT Column1, Column2 FROM Table1
WHERE Date LIKE "%2004" ; 

A little bit about the interview process:
The interviewer first asked me about a few questions about Tableau. For example: If I have performance issues with Tableau? If I have experience sharing the dashboard online with other people? How can I get the data from outside resource to Tableau? How can I connect two data at the same time in Tableau? How to change the data format when I upload the workbook to the public profile? 
Then we came to the chatting board to start the SQL questions. I listed the lessons I learned from the interview above. 

All the best to college students like me in the job market : ) 











September 28, 2014

Why did I create www.evafeng.com?

Inspired by a lot of excellent professionals in the data visualization field, I created the site to document the my path of exploring the data viz world. My old site was evasdatavisualization.weebly.com. At first, the old site was created only for presenting my projects in class. After I attended the Tableau Annual Conference 2014, I had a lot of inspiration and determination in creating my new site. I felt very lucky to get the domain name same as my name. I tried very hard to figure out the name of my new site. 

The named of the site is "Explore Viz Achieve". Did you notice that the initials of these three words are "E.V.A.", which is my name Eva? The name of the size is a snapshot of what I wanted to do in my career: 
Explore: Life is a journey. I would like to explore the stories behind the data and earn more data analysis skills. I want to explore the advanced programming tools and data visualization softwares to create awesome projects. I want to tell you the interesting stories I discovered in my projects. 
Viz: In the data analysis industry, there are so many branches of subjects, like data mining, statistical computing, data engineering, statistical programming, risk management and etc.. Among all these branches, nothing other than data visualization caught my constant attention. The practice of data visualization is a combination of my artistic side and scientific side. It created a balance for any professionals who are creative but also logical. It made the world of data more beautiful. 
Achieve: The last stage is to achieve our goals. The goal of each project is very unique. I hope my skills can help my future company to achieve their goal and mission. I hope my stories can inspire you to continue pursuing the data visualization. 
Thanks to my professor Jeffrey Shaffer. He taught Data Visualization class at the University of Cincinnati. His inspiring lecture encouraged a lot of students to start their career in data visualization and to invest their time in learning Tableau Software. I would like to invite you to visit his site at www.dataplusscience.com. He provided a lot of Tableau tutorials on his site. 

Tableau Annual Conference 2014

Sep 8 to Sep 12, a huge data party took place in Convention Center in Seattle. It was an amazing week for any data enthusiasts from the data visualization industry. If you miss the conference, just search #data14 on Twitter or Instagram. 

Monday Sep 8
Highlights of the Day: Lunch + Reception 

I had a great lunch with Andy Kriebel, Bryan Brandon, and Alberto Cairo at the Cheesecake Factory just across the street of the Convention Center. It was my first meeting with the members from the Data Viz Team of Facebook
Photo credits for Andy and Bryan. Andy shared his pictures on flickr. Check out here


Reception began in the late afternoon with the warm welcoming music. The giant rectangle screen streamed the live Twitter and Instagram data.. (Yes, we are pretty nerdy :P) 
At the reception, I had a great talk with the data viz professionals. I got to learn that Product Consultant at Tableau was not just a sales person but also a technician for the product. The Product Consultants are responsible for training the employees of Tableau's client companies to learn how to use Tableau in their company, promoting the sales of Tableau software, and generating the visualization for Tableau's client companies. 

And you might be surprised about the quality of food at the reception. They served sushi and yummy Chai Tea Latte. You could get California Rolls, Shrimp Rolls, and fresh Salmon Rolls as much as you wanted. : )

Tuesday Sep 9
Highlights of the Day: Christian Chabot's Keynote Speech + Data Night Out

I attended the fist Keynote by Tableau CEO Christian Chabot. People constantly applauded for the presentation of the new features of Tableau 8.2 Desktop. 

One of the amazing feature is that in the new version of Tableau you can connect the dashboard with a website server by using only 30 lines of Javascript. In a just second, you can finish searching all the constructions in Seattle and visualized it immediately on the dashboard. Another new feature is the story point. Now in one dashboard, you can create more than two pages by adding the story point on the top of the dashboard. Another amazing feature is the Tableau Cloud and the iPad version of Tableau, which gave people the another new option to show the clients the dashboard they made!

Tuesday night is a party night! Tableau reserved the Seattle Center for all the data enthusiasts who registered for the conference. Space Needle, Chihuly Garden and Glass, and EMP museum were free for anyone who came to the party!
(Sorry I did not have many pictures for it..) 


Wednesday Sep 10
Highlights of the Day: Neil deGrasse Tyson's Keynote Speech + Facebook talk + Facebook Party
Keynote on Wednesday was hosted by Neil deGrasse Tyson, whose talk was definitely one of the most funny talk at the conference. He listed some statements from newspaper he collected which included obvious statistical errors :P 


One of the featured talks on Wednesday was Facebook Jeopardy: Hack Edition. Andy and Bryan showed the audience how to grab the data from the server and visualized it on Tableau to study which stickers at Facebook was popular in a month. 

Another interesting featured talk on Wednesday was Porn, Pokemon, and Pop Culture: Using Data That Doesn't Suck. Andy, Jewel, and Peter told their story of Tableau using experience. Jewel's pokemon viz hit thousands of views on Reddit. Another great idea that might inspire fashion designers in NY is Jewel's dress. She collected the music type she listened everyday, generated a viz, and printed the viz on her dress!! A woman sitting in front of me took a picture when Jewel stood out in the front of the stage. 


The Facebook party was a great place for people to share their ideas and thoughts. They delivered nice T-shirts and stickers to people who came to the party. Regardless the party was set up in a bar which you might see in any city, they decorated the atmosphere of the bar with their unique Facebook logo. 


Thursday Sep 11
Highlights of the Day: Iron Viz Championship

My favorite professor at college Jeffrey Shaffer was one of contestants at the Iron Viz Championship. I want to say "Go Bearcat"! 
During the contest, three contestants used the same data of Yelp to create their own viz. You might wonder if Prof. Shaffer's viz is a donut chart but wait.. That's not a donut chart!! You can select a number randomly from the chart so the viz can give you the optional restaurant.. Feeling lucky, right? 

Friday Sep 12 
Friday is the exam day. You can get $100 discounted price for the Tableau exam. But is it something missing? You are right. What will happen next year Tableau Annual Conference 2015? 

SEE YOU IN LAS VEGAS!! 
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Extra

I got a very nice photo from the photo booth at the conference. Tableau streamed my photo on the big screen before the Keynote. I already use the picture as my Linkedin and Twitter profile pictures. 


I would like to end this pose with a picture of sunny Friday afternoon at Fremont as you know sunshine of Seattle, which is famous for rainy days, is very precious. :)