Posted inMY SQL Oracle PL/SQL SQL

SQL remove duplicates

Removing duplicates from a SQL database is a common task that can help improve data quality and query performance. Duplicates occur when there are multiple rows in a table with identical values in one or more columns. You can eliminate these duplicates using various SQL techniques and clauses. In this…
Posted inMY SQL Oracle PL/SQL SQL

SQL TCL statements

Transaction Control Language (TCL) in SQL is a subset of SQL commands used to manage database transactions. Transactions are a fundamental concept in database systems, ensuring data integrity and consistency by grouping a set of SQL statements into a single logical unit of work. TCL commands allow developers to control when changes…
Posted inMY SQL Oracle PL/SQL SQL

IF ELSE Statement

In the world of SQL Server, conditional logic is a powerful tool that enables developers to execute specific actions based on certain conditions. Among the most commonly used constructs for implementing conditional logic is the IF ELSE statement. This versatile control-flow tool allows you to make decisions and dictate the flow…
having vs where clause
Posted inSQL SQL Server

Having vs Where clause

When working with SQL Server, it’s crucial to understand how to filter and manage data effectively. Two powerful clauses, HAVING VS WHERE CLAUSE, serve as essential tools in SQL for applying conditions and narrowing down query results. Despite their similarities, they have distinct purposes and use cases. This blog will explore their differences,…
select in where clause
Posted inSQL SQL Server

SELECT in Where clause

In SQL Server, the SELECT statement within a WHERE clause is a powerful technique used to filter records based on a condition derived from another query. This is commonly achieved using a subquery, which is a query nested inside another query. Subqueries can return a single value, a list of values, or even a…
sql limit
Posted inMY SQL Oracle PL/SQL SQL

SQL LIMIT

Summary: in this tutorial, you’ll learn to use the SQL LIMIT clause to limit the number of rows returned from a query. Introduction to SQL LIMIT clause  To limit the number of rows returned by a SELECT statement, you use the LIMIT and OFFSET clauses. Here’s the syntax of LIMIT & OFFSET clauses: SELECT column_list FROM table1 ORDER BY column_list LIMIT row_count…
sql distinct
Posted inSQL Server MY SQL Oracle PL/SQL

SQL DISTINCT

Summary: in this tutorial, you will learn how to use the SQL DISTINCT operator to select distinct values from a table. Introduction to SQL DISTINCT operator  To select the distinct values from a column of a table, you use the DISTINCT operator in the SELECT clause as follows: SELECT DISTINCT column1 FROM table_name; In this syntax,…
sql order by
Posted inSQL Server MY SQL Oracle PL/SQL

SQL ORDER BY

Summary: In this tutorial, you’ll learn how to use the SQL ORDER BY clause to sort the result set based on values of one or more rows in ascending or descending orders. Introduction to SQL ORDER BY clause  The ORDER BY is an optional clause of the SELECT statement. The ORDER BY clause allows you to sort the…
SQL Sample Database
Posted inMY SQL Oracle PL/SQL SQL

SQL Sample Database

Summary: in this tutorial, you will learn about a SQL Sample Database called HR that manages the HR data of the small businesses. The following database diagram illustrates the HR sample database: SQL Sample Database The HR sample database has seven tables: The employees table stores the data of employees. The jobs table stores…
SQL SELECT
Posted inMY SQL Oracle PL/SQL SQL

SQL SELECT

Summary: in this tutorial, you will learn how to use the SQL SELECT statement to query data from a single table. Introduction to SQL SELECT statement The SELECT statement allows you to retrieve data from one or more tables. Here’s the basic syntax of the SELECT statement that retrieves data…