If you have been writing SQL queries for a while, you must be aware of the COUNT() function. It’s very simple to use, but it has multiple variations which often confuses people about when and exactly how to use them. In this tutorial, we are going to learn about different variations of COUNT functions and …
If you are looking to assemble a unique group of PostgreSQL developers for your team or to start a good career as a PostgreSQL developer, you have come to the right place. In this tutorial, we will provide you with a curated list of the most important PostgreSQL interview questions for advanced PostgreSQL developers, to …
Basic PostgreSQL Interview Questions and Answers Read More »
ROWS and RANGE are important SQL window functions. If you have been writing queries in SQL for a while, you may have experienced confusion regarding why there are two keywords for the same function, even when they give the same results in some situations. However, they are not the same! In this tutorial, we will …
ROWS and RANGE in Window Functions (With Examples) Read More »
If you have been writing queries in SQL, there must be various situations where you wanted to join the results obtained from two or more queries into a single result set, and you have wondered, “Is it possible to do that in SQL?”, Yes, it’s possible! In this tutorial, we will learn about different SET …
If you have been writing queries in SQL for a while, and you have faced certain situations where you need one query to use the result from another query, “Is it possible to use a Nested query in SQL?” is a question you could have. Yes, it’s possible! In this tutorial, we will learn about …
In SQL, the GROUP BY clause is used to put together rows with the same values in some columns into simple groups. It’s often used with total functions like SUM(), COUNT(), AVG() and more to do tasks on every set of rows instead of all the results. The GROUP BY rule helps to join and make data …
Common GROUP BY Error in SQL: A Troubleshooting Guide Read More »
In relational databases, such as Oracle, MYSQL Server, SQL and various others, the data is stored in numerous tables that are connected to one another with the same key value. As a result, there is an ongoing requirement to extract data from two or more tables into a result table based on certain criteria. This …
Joins are one of the remarkable features of SQL, where its ability to join tables together based on common features and the retrieval of data based on certain conditions allows data for the analysis process. In this tutorial, we will learn about the two types of SQL Joins, i.e. Equi Join and Non Equi Join, …
Equi Join and Non-Equi Join in SQL (With Examples) Read More »
In our day-to-day lives, we deal with a large amount of data with a high possibility of inconsistency. So, to filter out data based on a string and specific pattern, SQL provides a flexible way. In this tutorial, we will learn about the LIKE and NOT Like Operators in SQL, which perform pattern matching within …
SQL LIKE and NOT LIKE Operators: A Beginner’s Guide Read More »
In our day-to-day life, we keep our data in various logical tables in the relational database connected through a common key value. As a result, we may need to filter out some data values to get the desired result based on some conditions. And that’s where the JOIN clause comes into the picture. In this …