6 Advanced SQL Queries for Analyzing Financial Data by Tihomir Babic 12 Feb 2021 Are you an advanced SQL user who’s new to finance? Do you want to learn how to use your knowledge to analyze financial data? The article will give you some guidance. You probably know that SQL is a potent tool for analyzing all sorts of data. The bigger and more complex data, the more beneficial SQL becomes. In certain situations, financial data can be very complicated; producing a sophisticated analysis requires sophisticated tools. Read more Why Use SQL Over Excel by Shanika Wickramasinghe 25 Sep 2019 SQL is replacing Excel in many fields, and data analysis is certainly one of them. If you are still using Excel as a data analyst, you are missing something very valuable. SQL can make your life easier, as it's more efficient and faster than Excel. So, how and from where can you learn SQL? How Can SQL Help Data Analyst? You can use SQL to help you with the following work: Read more SQL Indexing 101 by Aldo Zelen 14 Aug 2018 Indexes are one of the most misused and misunderstood entities in physical database design. A good understanding of indexes and how they solve database performance problems is necessary for any database novice. In this article, we'll look at basic database indexes and their role in database development. To picture what an index is, consider a textbook. At the end of most textbooks is an index listing all the terms one can find in the text and the pages on which they appear. Read more How to Use a SQL Wildcard by Aldo Zelen 31 Jul 2018 SQL wildcard allows us to filter data matching certain patterns in SQL. We use SQL wildcards with the LIKE operator in the WHERE clause of a query to filter data. In this beginner’s article, we’ll look at everything you need to know about basic SQL wildcards. If you like playing cards, then you know that wildcards can substitute any other card in your deck. Similarly, SQL wildcards can substitute one or more characters. Read more Our Picks for 2020’s 7 Best Online SQL Schools by Dorota Wdzięczna 24 Jul 2018 If you’re looking for the best online SQL courses but aren’t sure where to start, you’re in the right place. I evaluated the top 7 ranked SQL schools available online to help you find the right solution. While summer is a great time to relax and get away from work, it’s also an excellent opportunity to learn new skills – like SQL! Thanks to SQL schools putting their courses on the internet, learning new tech skills is super easy and you can choose from a variety of formats to suit your needs. Read more Why Learn SQL Over the Summer by Kate Stolarek 6 Jul 2018 Think summer is reserved for flying to warm places and hanging out at the beach? Sure! But it's also a great time to learn new skills that you haven't had time for. If you recently graduated from high school and want to get a head start on computer programming for college, learning SQL over the summer is a great opportunity. You have nothing to lose and everything to gain—SQL is actually really easy to learn, especially with so much free time over the summer. Read more Key Insights for Mastering SQL Queries Using Tinder Data Example by Aldo Zelen 13 Jun 2018 Going from zero to one can be daunting in any endeavor. The same is true for learning new programming languages, even simple ones like SQL. In this article, we’ll take a look at some key insights that will help you understand the nuances of mastering SQL queries. If you’ve never used SQL, you’re in the right place. When learning anything new, you’ll find that there are always some key insights or tips that can help you on your way. Read more Improving Slow Query Performance: When Runtime Matters by Ignacio L. Bisso 8 Jun 2018 As SQL users, we usually focus on writing queries that return correct results. However, there are more things to consider when you're writing a query; one of them is query performance. In this article, we'll look at some examples where query response time is critical. Scene One: 911 Call Center Let's suppose we're at a 911 call center, when the phone rings. One of the operators answers the call; a witness reports that a man has been shot. Read more Converting Subqueries to Joins by Ignacio L. Bisso 8 May 2018 Not all queries are alike, especially in terms of performance. In this article, we'll look at how you can convert SQL subqueries to joins for improved efficiency. When should I use SQL subqueries? Great question! Unfortunately, there's no concrete answer. SQL beginners tend to overuse subqueries. Typically, once they find that SQL construction works in one situation, they try to apply that same approach to other situations. It's only natural. Read more Learn to Write a SQL Correlated Subquery in 5 Minutes by Ignacio L. Bisso 10 Apr 2018 If you’re familiar with the famous Russian nesting doll, then SQL correlated subqueries should be a peace of cake to understand—subqueries are just queries nested within queries. An SQL subquery is often called an “inner” query; the main query is usually called the “outer” query. This article covers everything you need to know about correlated subqueries. What Exactly is a SQL Correlated Subquery? A correlated SQL subquery is just a subquery that is executed many times—once for each record (row) returned by the outer (main) query. Read more How to Become a Database Analyst by Aldo Zelen 4 Apr 2018 Curious about becoming a database analyst? Maybe you've taken some database courses at university and they really struck a chord. Or maybe you learned online. Now you're thinking about making a career out of working with databases. Where would you start? What should you expect at each phase of your professional development? In this post, we'll explore the challenging and exciting world of databases analysis. We'll go from the very beginning of a career to the apex of professional success. Read more Extracting Data From a String: SPLIT_PART in PostgreSQL by Ignacio L. Bisso 29 Mar 2018 Learn how to use split_part in PostgreSQL to extract data from strings. Quite often, we’d like to extract parts of a string when working with text values. A common example is when we have a full name and need to retrieve only the last name. In this article, we’ll examine how to do it using split_part in PostgreSQL, i.e. a string-related function that can be used to extract a substring. Read more High-Performance Statistical Queries: Dependencies Between Discrete Variables by Dejan Sarka 15 Dec 2017 In my previous article, we looked at how you can calculate linear dependencies between two continuous variables with covariance and correlation. Both methods use the means of the two variables in their calculations. However, mean values and other population moments make no sense for categorical (nominal) variables. For instance, if you denote "Clerical" as 1 and "Professional" as 2 for an occupation variable, what does the average of 1.5 signify? Read more Digging Into Data: Explore and Analyze Survey Results With SQL by Kacper Skawina 29 Nov 2017 Excel is a powerful beast that lets you analyze complex data. Yet, operating on big chunks of data can sometimes be a daunting task. Let's take a look at how SQL can help. Today, we'll tackle a common problem with importing data to an SQL database, using a real-life example. Suppose your company conducted a survey on the most popular programming trends and preferences, striving to meet the expectations of its users. Read more SQL Hacks To Control Family Budget On Black Friday Weekend by Dorota Wdzięczna 23 Nov 2017 If you’re in the US, chances are you’ve been eagerly awaiting the approach of Black Friday just as much as Thanksgiving. Though the shopping frenzy takes hold of nearly everyone, some people have to stick to their budgets and shop prudently. In this article, we’ll take a look at how generating an SQL report can help you track how much your family spent shopping on Black Friday. Storing Black Friday Purchases in a Database Before we can create an SQL report, we first need some data we can use. Read more Introduction to Reporting with SQL — the Ultimate Tutorial for Business Professionals by Aldo Zelen 13 Nov 2017 Working with the financial aspects of large and small enterprises can be a daunting task for a business professional. In this article, we'll look at several ways of constructing the perfect SQL report. You've probably already heard about SQL from your colleagues or in other areas of your career. If you're here, you've likely concluded that learning SQL will make your professional life easier – and you're right! Read more SQL Statistical Analysis Part 1: Calculating Frequencies and Histograms by Dejan Sarka 28 Mar 2017 Database and Business Intelligence (BI) developers create huge numbers of reports on a daily basis, and data analyses are an integral part of them. If you wonder whether you can perform statistical analysis in SQL, the answer is ‘yes’. Read my article to learn how to do this! Statistics are very useful as an initial stage of a more in-depth analysis, i.e. for data overview and data quality assessment. However, SQL statistical analysis possibilities are somewhat limited as there are not many statistical functions in SQL Server. Read more