This week we’re talking about certifications. We’ll share an insider review of a popular data science certification, talk about SQL interview questions, and share some FinTech news.

This Week’s News and Resources

• DataCamp’s Certifications: Insider Review

• The 15 Best Python Courses Currently Available

• SQL Server Interview Questions (And Answers)

• Data Science Certification with an 87% Hiring Rate (TripleTen)

• Ansa Raises $14 Million for “Wallet-as-a-Service” (TechCrunch)

• SQL Certifications: An Overview

• PayPal Raises Profit Forecast (MSN / Reuters)

SQL Interview Questions (And Answers)

The community has shown an interest in SQL jobs, so we wanted to prepare you for upcoming interviews. Ready for the full guide? Here’s Hackr’s List of SQL Interview Questions.

As a quick refresher, here are two common SQL interview questions. . . and their answers.

What is a join in SQL? What are the types of joins?

A join is used to query data from multiple tables based on the relationship between the fields.

There are four types of joins:

Inner Join

Rows are returned when there is at least one match of rows between the tables.

SELECT first_name, last_name, order_date, order_amount
FROM customers AS c
INNER JOIN orders AS o
ON c.customer_id = o.customer_id;

/* customers and orders are two tables. Data will be displayed from the two tables where the customer_id from customer table matches

The customer_id from the orders table. */

Right Join

Right join returns all rows from the right table and those which are shared between the tables. If there are no matching rows in the left table, it will still return all the rows from the right table.

SELECT first_name, last_name, order_date, order_amount
FROM customers AS c
RIGHT JOIN orders AS o
ON c.customer_id = o.customer_id;

/* customers and orders are two tables. All rows from the Orders table is returned with matching rows from the Customers table if any */

Left Join

Left join returns all rows from the Left table and those which are shared between the tables. If there are no matching rows in the right table, it will still return all the rows from the left table.

SELECT first_name, last_name, order_date, order_amount
FROM customers AS c
LEFT JOIN orders AS o
ON c.customer_id = o.customer_id;

/* customers and orders are two tables. All rows from the customers table is returned with matching rows from the orders table if any */

Full Join

Full join return rows when there are matching rows in any one of the tables. This means it returns all the rows from the left-hand side table and all the rows from the right-hand side table.

SELECT first_name, last_name, order_date, order_amount
FROM customers AS c
FULL JOIN orders AS o
ON c.customer_id = o.customer_id;

/* customers and orders are two tables. All rows from the Orders table and customer table are returned */

What is the difference between DBMS and RDBMS?

A Database Management System (DBMS) is a software application that helps you build and maintain databases. A Relational Database Management System (RDBMS) is a subset of DBMS, and it is one based on the relational model of the DBMS.

We’re writing about SQL this week because you’ve shown an interest in the subject. If you find this helpful, please share our newsletter with a friend!

DataCamp’s Certifications To Get You Job-Ready: Insider Review

With a structured approach that spans from foundational principles to advanced applications, DataCamp's certifications bridge the gap between theoretical knowledge and practical skills. 

And there's more: each certification is delivered online and integrated into their premium subscription, making learning accessible and affordable.

But the real kicker? DataCamp ensures its certifications are tightly aligned with industry needs, focusing on the skills that employers truly value in the world of data. 

From SQL mastery to machine learning, their certifications prepare you for real-world tasks you’ll face in the job market today.

So, whether you're starting out or scaling up, DataCamp’s certifications are designed to validate your knowledge and hands-on experience. 

Now, let's explore these certifications in more detail to see just how they stack up! Read my full review, or . . .

This Week’s Jobs

Here are a few specific job opportunities you might be interested in.

• SQL Jobs - All Locations (including Remote)

• Jobs at Oracle - USA and UK

• Python Jobs - USA

• Cybersecurity Jobs this Week - All Locations (including Remote)

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