https://www.datacamp.com/community/podcast/critical-thinking-in-data-science

<p>Debbie Berebichez, Chief Data Scientist at Metis, speaks with Hugo about what type of critical thinking skills are necessary in data science.</p>

Debbie Berebichez speaks with Hugo about the importance of critical thinking in data science.

Critical Thinking in Data Science

https://www.datacamp.com/community/blog/critical-thinking-in-data-science

https://www.datacamp.com/community/podcast/credibility-crisis-in-data-science

<p>Skipper Seabold, a Director of Data Science at Civis Analytics, discusses the current and looming credibility crisis in data science.</p>

Skipper Seabold, a Director of Data Science at Civis Analytics, discusses the current and looming credibility crisis in data science.

The Credibility Crisis in Data Science

https://www.datacamp.com/community/blog/credibility-crisis-in-data-science

https://www.datacamp.com/community/news/the-credibility-crisis-in-data-science-with-skipper-seabold-6bbmgpwy1qm

The Credibility Crisis in Data Science (with Skipper Seabold)

https://www.datacamp.com/community/news/reducing-rework-as-an-sql-data-analyst-s8wigs0qm3

In this tutorial, you will learn how to maximize your productive time in SQL.

Reducing Rework as an SQL Data Analyst

https://www.datacamp.com/community/news/sql-tutorial-how-to-write-better-queries-d2nj398ov1l

Structured Query Language (SQL) is an indispensable skill in the data science industry and generally speaking, learning this skill is fairly easy. However, most forget that SQL isn't just about writing queries, which is just the first step down the road. Ensuring that queries are performant or that 

SQL Tutorial: How To Write Better Queries

<p><iframe width="560" height="315" src="https://www.youtube.com/embed/CexYyrtIAjw" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe></p>
<h2 id="can-you-tell-us-about-your-background-">Can you tell us about your background?</h2>
<p>My career began in 2010 in the Air Force working in the field of Security Forces, more commonly known as Military Police. I was involved in physically securing government facilities in South Korea and Japan,  and even got to guard Obama’s plane once! After leaving the Air Force, I worked in Telecommunications for a number of years as a help desk analyst before moving on to Cybersecurity in the banking domain.</p>
<p>Despite not working in a role that required data skills, I always tried to use them wherever I found myself working, occasionally to the annoyance of my boss, who told me “stick to your day job” 😂.  However, there were many times where being the team’s “data guy” was helpful in these roles, like generating informative Tableau reports for management, finding unused data and putting it to use, and identifying insights that were not fully realized before advanced analysis.  </p>
<p>More recently, I’ve gained a proper job as a data analyst on a data science team where I finally get to put these skills to use everyday. I found myself unemployed during the pandemic in November 2020 and saw this as a good chance to make a big career change to work with data full time. I went from cybersecurity analyst in banking to data analyst in the publishing industry.  DataCamp helped me gain skills that made me marketable enough to be able to make this career move and I plan to move to a data scientist role in the very near future!</p>
<p>I studied software development in school, but I’m a very big proponent of teaching myself the relevant skills I need online rather than throwing money at Higher Ed. I’ve found great value in free or affordable online resources like DataCamp. On the personal side, I enjoy participating in competitions on DrivenData.com and Kaggle, studying Japanese, playing guitar, and of course, knocking out modules on DataCamp.</p>
<h2 id="around-how-much-time-do-you-dedicate-to-learning-on-datacamp-">Around how much time do you dedicate to learning on DataCamp?</h2>
<p>About 2-3 hours a day.</p>
<h2 id="how-did-you-find-datacamp-and-why-did-you-choose-our-platform-over-other-online-learning-platforms-">How did you find DataCamp and why did you choose our platform over other online learning platforms?</h2>
<p>It’s been so long that I can&#39;t really remember how I found DataCamp. More than likely, I was just searching for data science learning resources. I do remember checking out DataQuest, and I didn’t go with them because their UI kind of hurt my brain. On DataCamp, everything is laid out in a very minimal and consistent way. It’s very easy to find what I’m looking for.</p>
<h2 id="how-has-datacamp-positioned-you-to-meet-your-professional-goals-">How has DataCamp positioned you to meet your professional goals?</h2>
<p>My new job mostly involves writing Python code. Code that wrangles, cleans, and gets data from point A to point B. Sometimes some SQL gets thrown in the mix, and DataCamp has provided 98% of all my real-world SQL knowledge and education that I couldn’t gain from my previous employment. DataCamp has certainly made my new job a breeze.</p>
<h2 id="what-are-the-skills-you-ve-learned-on-datacamp-that-have-proven-to-be-most-useful-">What are the skills you’ve learned on DataCamp that have proven to be most useful?</h2>
<p>Oh, that is a difficult one. I would say general machine learning skills. It took me a very long time to wrap my head around scikit-learn and how to do something as simple as using train_test_split(). It was very intimidating at first. After getting a lot  of guided repetition in, it all made sense overnight. I continue to learn new tips and tricks on the <a href="https://www.datacamp.com/tracks/machine-learning-fundamentals-with-python">Machine Learning Scientist with Python</a> career track that I continually apply to my real-world projects.  </p>
<p>A great example that I’m proud of is building a spam classifier for Bank of America’s Email Abuse team, within their Security Operations Center. Their job is to analyze suspicious emails that internal employees report to their team. They receive great volume of submissions and many of those are junk (or spam). To help automate the processing of these submissions, I built a Logistic Regression spam filter with an accuracy of 93%. Eventually, this was put into production and saved approximately 200 weekly analyst hours. This allowed their team to focus on more pressing tasks.</p>
<p>In my current job, I’ve recently had to build a complex data pipeline (in Python and SQL) that pulls data from an SFTP server, does intensive data cleaning  on it, joins that data on a table from a SQL Server database, then forwards the end result to Jira. DataCamp’s course <a href="http://datacamp.com/courses/writing-efficient-python-code">Writing Efficient Python Code</a> helped me make this script 10 times faster and the <a href="http://datacamp.com/tracks/sql-fundamentals">SQL Fundamentals</a> skill track really helped with the SQL portion of this script.</p>
<p>Currently, I’m working on the <a href="https://www.kaggle.com/c/nlp-getting-started/overview">Disaster Tweet Competion on Kaggle</a>. To assist with building my solution, I’m going through the <a href="https://datacamp.com/tracks/natural-language-processing-in-python">Natural Language Processing in Python</a> skill track for guidance while simultaneously applying these concepts to the Kaggle project.</p>
<h2 id="what-do-you-most-like-about-datacamp-">What do you most like about DataCamp?</h2>
<p>The relevancy, variety, and quality of courses. On relevancy: Many of the courses age well. After three years, I still look back on some of the older courses for help.</p>
<h2 id="do-you-have-any-advice-for-someone-just-starting-out-with-datacamp-">Do you have any advice for someone just starting out with DataCamp?</h2>
<p>Think of a data project that you’d like to do in real life, then identify what skills you need to do that project, then look on DataCamp for a course on that skill. Complete that course and then give that project a shot.</p>
<p>For new learners who don’t know where to start, begin with one of the career tracks that pique your initial interest. Then pivot to something else as you learn what is out there! 😊</p>
<p>I also recommend checking out DataCamp’s <a href="http://datacamp.com/webinars">webinars</a>, which have exposed me to many great minds in the field of data science.</p>
<p><em>Looking for a community of data enthusiasts for support in your learning journey? Join the <a href="https://support.datacamp.com/hc/en-us/articles/360001915993-The-DataCamp-Slack-Community-An-Overview">DataCamp Slack Community</a>, tell the world you’re a data enthusiast with a <a href="https://www.datacamp.com/community/blog/linkedin-covers">custom LinkedIn cover image</a>, and connect with Patrick <a href="https://www.linkedin.com/in/patrickkellyofficial/">on LinkedIn</a>.</em></p>


https://www.datacamp.com/community/blog/patrick

Q&A with Patrick Kelly, Professional Data Wrangler

Learner Spotlight: My Journey from Cybersecurity Professional to Data Analyst [Testimonial] | DataCamp

Learner Spotlight: My Journey From  Cybersecurity Professional to Data Analyst [Testimonial]

https://www.datacamp.com/community/blog/chris-murphy

Chris Murphy studied international business and worked at a Chinese e-commerce startup. He used DataCamp to land a role as a Data Analyst at UMass Medical School.

Learner Spotlight: How I Became a Data Analyst with DataCamp [Testimonial]| DataCamp

Learner Spotlight: How I Became a Data Analyst with DataCamp [Testimonial]

<h2>Retrieving Data From The Database</h2><p>This chapter provides a brief introduction to working with relational databases in a marketing context. You'll learn about their structure,  how to talk about them using database lingo, and how to begin an  analysis by using simple SQL commands to select and summarize columns  from database tables.</p><h2>Filter Data And Limit Your Output</h2><p>In this chapter, you'll learn how to filter tables for rows that satisfy your criteria of interest with the help of basic comparison operators and combinations of multiple criteria.</p><h2>What's Next?</h2><p>Besides selecting columns and filtering rows, there is much more that you can do with SQL! This chapter will present you with some examples that will motivate you to continue to develop this newly gained skill!</p>

https://www.datacamp.com/community/open-courses/sql-tutorial-for-marketers

The best marketers and growth hackers are data-driven. Learn how to use Structured Query Language (SQL) to query a database containing bank clients and marketing campaigns data.

SQL Tutorial for Marketers

https://www.datacamp.com/community/tutorials/sql

Are you ready to begin your SQL journey? Here’s a step-by-step guide on how to get started.

SQL Tutorial for Beginners | DataCamp

SQL Tutorial for Beginners

<p>SQL Server is a relational database management system. One of the key principles of the relational database is that data is stored across multiple tables.</p>
<center><img src="https://res.cloudinary.com/dyd911kmh/image/upload/c_scale,f_auto,q_auto:best,w_564/v1603485855/join1_nitybm.png" /></center>

<p>We will need to be able to join tables together in order to extract the data we need. We use <code>primary</code> and <code>foreign</code> keys to join tables.</p>
<h2 id="primary-key">Primary Key</h2>
<p>A primary key is a column that is used to uniquely identify each row in a table. This uniqueness can be achieved by using a sequential integer as an identity column. Or sometimes, existing columns naturally contain unique values, and they can be used.</p>
<p>In the below example, we can see the first few rows from the <code>artist</code> table. It has two columns, <code>artist_id</code>, and <code>name</code>. The <code>artist_id</code> column acts as a primary key for this table, it is an integer column, and each value is different.</p>
<pre><code>+-----------+-------------------+
| artist_id | name              |
|-----------+-------------------|
| 1         | AC/DC             |
| 2         | Accept            |
| 3         | Aerosmith         |
| 4         | Alanis Morissette |
| 5         | Alice In Chains   |
+-----------+-------------------+
</code></pre><p>Now let&#39;s look at the <code>album</code> table. Can you spot the primary key? Yes, it&#39;s the <code>album_id</code> column. It&#39;s common for the primary key to be named &quot;table-name underscore id&quot;. But, you&#39;ll have noticed there is also an <code>artist_id</code> column. That also consists of integers and has the same name as the <code>artist_id</code> column in the artist table. What does this mean?</p>
<pre><code>+----------+-------------------------+-----------+
| album_id | title                   | artist_id |  
|----------+-------------------------+-----------|
| 1        | For Those About To Rock | 1         |
| 2        | Balls to the Wall       | 2         |
| 3        | Restless and Wild       | 2         |
| 4        | Let There Be Rock       | 1         |
| 5        | Big Ones                | 3         |
+----------+-------------------------+-----------+
</code></pre><h2 id="foreign-keys">Foreign Keys</h2>
<p>Well, from the previous output, it is clear that the <code>artist_id</code> in the artist table acts as a <code>Foreign_key</code> to the album table. The <code>FOREIGN KEY</code> constraint is used to prevent actions that would destroy links between tables.</p>
<ul>
<li><code>artist</code> table</li>
</ul>
<pre><code>+-----------+-------------------+
| artist_id | name              |
|-----------+-------------------|
| 1         | AC/DC             |
| 2         | Accept            |
| 3         | Aerosmith         |
| 4         | Alanis Morissette |
| 5         | Alice In Chains   |
+-----------+-------------------+
</code></pre><ul>
<li><code>album</code> table</li>
</ul>
<pre><code>+----------+-------------------------+-----------+
| album_id | title                   | artist_id |  
|----------+-------------------------+-----------|
| 1        | For Those About To Rock | 1         |
| 2        | Balls to the Wall       | 2         |
| 3        | Restless and Wild       | 2         |
| 4        | Let There Be Rock       | 1         |
| 5        | Big Ones                | 3         |
+----------+-------------------------+-----------+
</code></pre><p>This means that when the <code>artist_id</code> in the album table matches the <code>artist_id</code> in the artist table, those rows can be linked as a <code>JOIN</code>.</p>
<h2 id="joining-album-and-artist">Joining Album and Artist</h2>
<p>Rows 1 and 4 of the artist table have an <code>artist_id</code> of 1. The <code>artist_id</code> 1 in the artist table is AC/DC. So, when we join the two tables together, we return the album details from the album table, and the corresponding artist details from the artist table - joined using the <code>artist_id</code> field, which is common to both tables.</p>
<p>This is known as an <code>inner</code> join.</p>
<pre><code class="lang-SQL">SELECT
  album_id,
  title,
  album.artist_id,
  name AS artist_name
FROM album
INNER JOIN artist ON artist.artist_id = album.artist_id
WHERE album.artist_id = 1;
</code></pre>
<pre><code>+----------+-------------------------+-----------+-------------+
| album_id | title                   | artist_id | artist_name |
|----------+---------------------------------------+-----------|
| 1        | For Those About To Rock | 1         | AC/DC       |
| 4        | Let There Be Rock       | 1         | AC/DC       |
+----------+-------------------------+-----------+-------------|
</code></pre><p>We joined the album and artist tables by matching the <code>artist_id</code> from the artist table to the <code>artist_id</code> in the album table.</p>
<p>When selecting columns with the same name from different tables, you must fully qualify the column name. Otherwise, SQL Server will not know which table to <code>SELECT</code> the column from.</p>
<p>To fully qualify a column, you have to prefix it with the relevant table name, followed by a period.</p>
<h3 id="inner-join-syntax">Inner Join Syntax</h3>
<p>Here&#39;s a generic example to remind you of the syntax. When we select the relevant columns from the main table, <code>table_A</code> in this case, then select any additional column we want to join to, which in this case is <code>table_B</code>. Then we specify the join using the keywords <code>INNER JOIN</code> and <code>ON</code>, providing the necessary key columns from both the tables.</p>
<pre><code class="lang-sql">SELECT
    table_A.columnX,
    table_A.columnY,
    table_B.columnZ,
FROM table_A
INNER JOIN table_B ON table_B.foreign_key = table_A.primary_key;
</code></pre>
<h2 id="not-using-a-where-clause">Not Using a <code>WHERE</code> Clause</h2>
<p>In this example, we don&#39;t specify a <code>WHERE</code> clause, so we return ALL combinations of ALL matches between the artist and album tables, again, based on the <code>artist_id</code> column, which is common to both.</p>
<pre><code class="lang-SQL">SELECT
  album_id,
  title,
  album.artist_id,
  name AS artist_name
FROM album
INNER JOIN artist on artist.artist_id = album.artist_id;
</code></pre>
<pre><code>+----------+---------------------------------------+-----------+
| album_id | title                   | artist_id | artist_name |
|----------+---------------------------------------+-----------|
| 1        | For Those About To Rock | 1         | AC/DC       |
| 4        | Let There Be Rock       | 1         | AC/DC       |
| 2        | Balls To The Wall       | 2         | Accept      |
| 3        | Restless and Wild       | 2         | Accept      |
+----------+---------------------------------------+-----------+
</code></pre><h2 id="multiple-inner-join">Multiple Inner Join</h2>
<p>You can also join more than two tables using <code>INNER JOINS</code>. You simply provide an additional <code>INNER JOIN</code> for each combination of tables. In our code below, we join tables A and B, and also B and C.</p>
<pre><code class="lang-SQL">SELECT
  table_A.columnX,
  table_A.columnY,
  table_B.columnZ table_C columnW
FROM table_A
INNER JOIN table_B ON table_B.foreign_key = table_A.primary_key
INNER JOIN table_C ON table_C.foreign_key = table_B.primary_key;
</code></pre>
<p>To learn more about joining tables, please see this video from our course <a href="https://campus.datacamp.com/courses/introduction-to-sql-server/joining-tables?ex=1">Introduction to SQL Server</a>.</p>
<iframe width="560" height="315" src="https://www.youtube.com/embed/DRDFtejKZs8" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

<p>This content is taken from DataCamp’s <a href="https://www.datacamp.com/courses/introduction-to-sql-server">Introduction to SQL Server</a> course by John MacKintosh.</p>


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