MySQL Examples and Tutorials
The OVER() clause is used to perform a calculation on the current row from the table with other rows of the table. The OVER() clause works along with the window function. The simple function or clauses available in the SQL language can not perform a calculation on an individual element from a specific row. OVER() …
Moving average is related to the time-series databases where we try to calculate an average for all the data points for a particular period. The different databases contain different types of data. Some hold data related to users that visit websites, healthcare data, or some kind of periodic data. This technique is mainly used for …
Programming languages like C, C++, Python, and Java possess the order of precedence and associativity for operators. There is a pre-determined order that determines which operator will execute sooner in implementation. A parallel concept is available in SQL, where the order of operation is pre-determined. When we write a query to crack problems, it contains …
There are diverse kinds of queries known in the SQL language. All the queries which are implemented under another query are comprehended as subqueries. One more query is executed beneath another query, which is an inline query. The inline query is distinct from the subqueries or derived query. In this article, we will understand the …
Introduction to SQL Inline Query: Syntax and Examples Read More »
In many cases, we need some data in the form of strings. The strings contain different characters. Sometimes, unwanted junk characters affect the accuracy of the outcome. Junk characters can cause complications while analyzing the table data elements. There are various strategies available in all types of programming languages to remove them. In this article, …
How to Remove Whitespaces & Junk Characters in SQL Read More »
The correlated subqueries are used in many codes to solve complex problems. Different types of subqueries are available, like nested subqueries, correlated subqueries, single and multiple-row subqueries, and multiple-column subqueries. All have various applications and advantages. In this article, we will see the details of the correlated subqueries. The subqueries are considered correlated when the …
The subqueries in SQL are the queries that are inside another query. This query can be set inside any clause like WHERE, HAVING, FROM, etc. These subqueries are likewise known as nested queries. The major aim of subqueries is to retrieve data from the table. It is also used as a condition to fetch the …
In relational databases, we deal with various data values with different data types. The date and time values can also be a part of the database. Sometimes, we need to deal with these values as well. In this article, we are going to study the calculation performed on date and time related values. Let me …
Performing Calculations On Date-Time Related Values Read More »
New developers often get confused between NULL, empty and zero values. However, it is not that complicated. In this tutorial, we will be learning what is the NULL value and what is the IS NULL operator in PostgreSQL. So, let’s get started! Introduction to PostgreSQL IS NULL Operator In any programming language, the NULL value …
The UNIQUE constraint, as the name suggests, enforces the table to contain the unique data. In this tutorial, we will be learning about the unique constraints in PostgreSQL with some examples. So, let’s get started! Also Read: PostgreSQL SELECT Statement PostgreSQL UNIQUE Constraint Introduction In the application, you often need the table column to have …
PostgreSQL UNIQUE Constraint: Introduction, Syntax & Examples Read More »