Aggregate window functions allow users to efficiently generate output such as comparing specific rows output to average across all rows or calculating cumulative sum by applying the aggregate result to every row of the data. This often helps developers to make their models efficient. In this tutorial, we will learn about the multiple aggregate function …
PostgreSQL Aggregate Functions: A Detailed Guide Read More »
If you have writing queries in PostgreSQL for longer, and you want to select data based on specific conditions in PostgreSQL, you can use the CASE statement within your SELECT query to perform conditional selection based on specific criteria. In this tutorial, you will learn about the CASE statement in PostgreSQL and explore how it …
PostgreSQL Conditional Select With CASE Statements Read More »
Mathematical operations are one of the most important requirements in programming languages and database design. Developers are provided with pre-built tools for manipulating the data. This function makes coding more efficient and accurate. PostgreSQL provides a collection of mathematical functions that enable users to improve data processing. This is the most asked topic in PostgreSQL …
PostgreSQL Mathematical Functions: A Detailed Guide Read More »
Correlated and nested subqueries in database management provide powerful tools for efficient data retrieval. Correlated subqueries use values from external queries to retrieve complex data, while nested subqueries insert one query into another, operating independently. In this tutorial, we will examine their syntax, execution, and practical application by example on various types. Correlated Subquery: An …
Difference Between Nested and Correlated Subqueries Read More »
Data aggregation is one of the important concepts when we talk about databases. If you have writing queries in SQL for a while, you must have come across the GROUP BY clause. In this tutorial, we will present some GROUP BY examples and demonstrate how they can be solved to extract valuable insights from data …
If you have been writing SQL queries for a while, you must know the importance of the WHERE clause. When it comes to data extraction based on specific conditions. However, there are some limitations you must have faced while trying to use the window function in WHERE clauses and the limitation can seem confusing at …
Window Functions Are Not Allowed in WHERE Clauses Read More »
If you have been writing SQL queries for some time you must have faced challenges while comparing dates. The reason is that the format of the table date must match the format of the input data. There might be certain situations in which TimeStamp and DATETIME formats can be used instead of date. In this …
While writing queries in SQL during the learning phase, we mostly join the table in which there are common columns or some kind of relationship between them. But, real-life scenarios are more complex and there are times when we are required to join the tables without any common column between them. In this tutorial, we …
How to Combine Two Tables Without a Common Column Read More »
While writing SQL queries, one of the fundamental operations is to sort the data, which is often done using the “ORDER BY” clause. However, in certain situations, we deal with “NULL” values and wonder if they come first or last when we use the ORDER BY clause. In this tutorial, we will learn about how …
Handle NULL When Working with ORDER BY Clause in SQL Read More »
SQL queries use the HAVING and WHERE clauses to filter the data. However, the WHERE clause cannot be used with the aggregate functions, which is where the HAVING clause comes into the picture! In this tutorial, we will learn about filtering data with HAVING and WHERE clause and their uses and differences between them with …