MySQL Examples and Tutorials
Indexes play a vital role when it comes to the SQL server. While writing SQL queries if you want to increase the performance and data retrieval timing, an index can play a crucial role in that. To understand better, let’s take a dictionary as an example, it has an index and with the help of …
Difference Between Clustered and Non-Clustered Index Read More »
If you have been writing SQL queries for longer, you must know the significance of GROUP BY and NULL values and how they contribute the most while managing and manipulating data values. NULL values represent the absence of a value or an unknown value in a database column, while the GROUP BY clause is used …
While dealing with a vast amount of data, there’s often a need to fetch the top value of the database, and going through the entire dataset for this procedure can be time-consuming. That’s where MySQL LIMIT and BETWEEN come into the picture. It allows users to extract the cream of the crop without sifting through …
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 …