Transaction Control Language (TCL) is a subset of SQL commands used to manage transactions in a database. Transactions are important for maintaining the integrity and consistency of data. They allow multiple database operations to be executed as a single unit of work, which either entirely succeed...
The full form of SQL is Structured Query language. It is a very useful tool to access or modify the structure and the data of the database. Many applications need the database to store the necessary data in a database in structured format permanently. MySQL, Oracle, SQL Server, etc. are...
What are SQL Queries and SQL Statements? Queries are requests for information or data from tables or combinations of tables in a database. Data analysis tools can generate pictorials, graphs, or complex graphs as the result of Structured Query Language (SQL) queries. There are four componen...
In the previous article we’vepracticed SQL, and today, we’ll continue with a few more SQL examples. The goal of this article is to start with a fairly simple query and move towards more complex queries. We’ll examine queries you could need at the job interview, but also some you wo...
A complex SQL query to illustrate the use of COALESCE function. Suppose we want to know the salaries of all the employees in the firm. But in the employee’s table, we can see that the salaries of all employees have not been mentioned. However, hourly rates and commission of employees wi...
In this lesson, we will learn about SQL sub-queries which are nothing but 'queries within another query'. Sub-queries are often used in more complex SQL statements to extract data from multiple tables. What Is a Sub-Query? A sub-query is a query which is defined within another SQL ...
User-defined functions (UDFs):SQL allows you to create user-defined functions, which are custom functions that can be used in SQL queries. UDFs enable you to encapsulate complex data cleaning operations into reusable functions, making your cleaning tasks more modular and maintainable. ...
SQL Complex Queries: Functionality & Examples4:48 SQL: Inner Joins SQL: Left & Right Joins SQL: Full Outer Joins2:38 SQL: Cross Joins4:13 SQL: Self-Joins Aliases in SQL: Syntax & Examples Next Lesson Practical Application for Database Programming: Displaying Data from Different Tables ...
This tip explores how to handle NULL values in SQL Server using the COALESCE() function using various queries and reviewing the results.
Rick F. van der Lans explains how SQL's GROUP BY clause groups rows on the basis of similarities between them. He goes on to explain the use of adding aggregation functions to display summations, averages, frequencies, and subtotals.