What FULL JOIN Is and When to Use It by Zahin Rahman 13 Apr 2021 Learn about FULL JOIN, how to implement it, how it compares with the other types of SQL JOINs, and some of its unique use cases. Before we jump into FULL JOINs, let’s quickly recap what an SQL JOIN is. At its core, a JOIN combines data from two or more tables within a database. Tables are usually linked together using unique identifiers in each table, i.e. primary and foreign keys. Read more SQL CTE Explained by Zahin Rahman 8 Apr 2021 In this article, you will learn about SQL Common Table Expressions (CTEs). This powerful SQL tool will help you simplify complex queries. Additionally, I will introduce you to the two main types of CTEs and some of their use cases. CTE Primer The Common Table Expression (CTE) was introduced to standard SQL to simplify long, complex queries (especially joins and subqueries). It is a temporary data set returned by a query that contains data separate from the main query. Read more Why Learn SQL Window Functions in 2021? by Zahin Rahman 22 Jan 2021 SQL window functions provide some extremely powerful and convenient features for data practitioners. This article explains why you should learn window functions and when you should use them. I’ll also provide some examples to help you visualize the concepts. Window functions are part of advanced modern SQL – knowledge of which will definitely enrich the repertoire of any SQL user. Window functions have a broad range of uses and can be applied to almost all facets of business. Read more Where Can I Find Good SQL CTE Exercises? by Zahin Rahman 21 Jan 2021 Find the top online resources for SQL Common Table Expression (CTE) exercises! CTEs allow you to structure and organize SQL queries efficiently, which is essential if you want to advance your SQL knowledge. A Common Table Expression, or CTE, is a SQL syntax that creates a temporary data set. This set contains separate data than the main query, which can typically be referenced or reused in a subsequent query. A CTE is considered temporary because the result is not permanently stored anywhere and only exists for the duration of the query. Read more Best Online Courses for SQL Window Functions by Zahin Rahman 16 Dec 2020 In this article, I will summarize the top online tutorials and courses available on SQL window functions for enthusiasts of data analysis, data science, and data engineering. The information is here to help you embrace the topic with ease and feel comfortable using window functions in SQL databases. SQL window functions can help you solve some of the most common analysis challenges in business: What are the N most popular products for each month of the year? Read more Top 7 Online Courses for Data Engineers by Zahin Rahman 11 Nov 2020 This article summarizes the top online courses available for data engineers. We have picks suitable for beginners as well as intermediate learners. If you’re interested in database design and management, check these courses out! Most individuals who aspire to enter the realm of data aim for data scientist or data analyst roles. While these roles are indeed very rewarding because of their tangible links to customers and business direction, the role of data engineers is equally vital for businesses that operate in a data-rich environment. Read more SQL HAVING Tutorial by Zahin Rahman 14 Oct 2020 Learn how to use the SQL HAVING clause to filter groups using your own specified conditions. The SQL HAVING clause is often a challenging concept to grasp, especially for beginners. Additionally, its specific use cases can be difficult to visualize without specific examples based on real-world datasets. In this tutorial, you will learn how to apply the SQL HAVING clause to filter groups of records based on specified conditions. You’ll see examples where we apply this concept to solving business problems on a realistic dataset. Read more How to Find Duplicate Values in SQL by Zahin Rahman 2 Sep 2020 Duplicate records waste time, space, and money. Learn how to find and fix duplicate values using SQL’s GROUP BY and HAVING clauses. Database best practices usually dictate having unique constraints (such as the primary key) on a table to prevent the duplication of rows when data is extracted and consolidated. However, you may find yourself working on a dataset with duplicate rows. This could be because of human error, an application bug, or uncleaned data that’s been extracted and merged from external sources, among other things. Read more Using GROUP BY in SQL by Zahin Rahman 21 Jul 2020 Now that you know SQL’s core commands, power up your queries with the GROUP BY clause and aggregate functions. GROUP BY is a SQL clause that arranges data into groups based on a common value (or values). It is widely used to obtain summary information for large datasets as well as for computing basic aggregate statistics. Once you have grasped SQL’s basic commands like SELECT, WHERE, and JOIN, mastering the GROUP BY clause can help you implement your SQL knowledge in real-world business intelligence scenarios. Read more How to Learn SQL JOINs by Zahin Rahman 2 Jun 2020 JOINs are one of the most fundamental and commonly used SQL commands for manipulating and querying real-world data sets. They are also one of the more challenging SQL topics to master! In this article, you’ll learn an effective strategy to learn the different types of SQL JOINs. When data is stored in a single table, we can easily retrieve rows and get all the information we need. But when businesses scale, so does their data. Read more «« « 1 2 » »»