SQL operators are important in DBMS as they allow us to manipulate and retrieve data efficiently. Operators in SQL perform arithmetic, logical, comparison, bitwise, and other operations to work with database values. Understanding SQL operators is crucial for performing complex data manipulations, calculations, and filtering operations in queries.
Operators in SQL
SQL operators are symbols or keywords used to perform operations on data in SQL queries. These operations can include mathematical calculations, data comparisons, logical manipulations, other data-processing tasks. Operators help in filtering, calculating, and updating data in databases, making them crucial for query optimization and accurate data management.
Types of SQL Operators
SQL operators can be categorized based on the type of operation they perform. Here are the primary types of SQL operators:
- Arithmetic Operator
- Comparison Operator
- Logical Operator
- Bitwise Operators
- Compound Operators
- Special Operators
Each of these operators is essential for performing different types of operations on data in SQL databases.
SQL Arithmetic Operators
Arithmetic operators in SQL are used to perform mathematical operations on numeric data types in SQL queries. Some common arithmetic operators:
Operator | Description |
---|
+ | The addition is used to perform an addition operation on the data values. |
- | This operator is used for the subtraction of the data values. |
/ | This operator works with the 'ALL' keyword and it calculates division operations. |
* | This operator is used for multiplying data values. |
% | Modulus is used to get the remainder when data is divided by another. |
Example: Arithmetic Operations
In this example, we calculates a 5% increment on employee salaries and returns both the original and updated salary values.
Query:
SELECT emp_salary, emp_salary * 1.05 AS "Revised Salary" FROM employee;
Output:
Arithmetic Operation ExampleSQL Comparison Operators
Comparison Operators in SQL are used to compare one expression's value to other expressions. SQL supports different types of comparison operator, which are described below:
Operator | Description |
---|
= | Equal to. |
> | Greater than. |
< | Less than. |
>= | Greater than equal to. |
<= | Less than equal to. |
<> | Not equal to. |
Example: Comparison Operation
In this example, we will retrieve all records from the "MATHS" table where the value in the "MARKS" column is equal to 50.
Query:
SELECT * FROM MATHS WHERE MARKS=50;
Output:
SQL Logical Operators
Logical Operators in SQL are used to combine or manipulate conditions in SQL queries to retrieve or manipulate data based on specified criteria..
Operator | Description |
---|
AND | Logical AND compares two Booleans as expressions and returns true when both expressions are true. |
OR | Logical OR compares two Booleans as expressions and returns true when one of the expressions is true. |
NOT | Not takes a single Boolean as an argument and change its value from false to true or from true to false. |
Example: Logical Operation
In this example, retrieve all records from the "employee" table where the "emp_city" column is equal to 'Allahabad' and the "emp_country" column is equal to 'India'.
Query:
SELECT * FROM employee WHERE emp_city =
'Allahabad' AND emp_country = 'India';
Output:
SQL Bitwise Operators
Bitwise operators in SQL are used to perform bitwise operations on binary values in SQL queries, manipulating individual bits to perform logical operations at the bit level. Some SQL Bitwise Operators are:
Operator | Description |
---|
& | Bitwise AND operator |
| | Bitwise OR operator |
^ | Bitwise XOR (exclusive OR) operator |
~ | Bitwise NOT (complement) operator |
<< | Left shift operator |
>> | Right shift operator |
SQL Compound Operators
Compound operators combine an operation with assignment. These operators modify the value of a column and store the result in the same column in a single step. Some Compound operators are:
Operator | Description |
---|
+= | Add and assign |
-= | Subtract and assign |
*= | Multiply and assign |
/= | Divide and assign |
%= | Modulo and assign |
&= | Bitwise AND and assign |
^= | Bitwise XOR and assign |
|= | Bitwise OR and assign |
SQL Special Operators
SQL also provides several special operators that serve specific functions such as filtering data based on a range, checking for existence, and comparing sets of values.
Operators | Description |
---|
ALL | ALL is used to select all records of a SELECT STATEMENT. It compares a value to every value in a list of results from a query. The ALL must be preceded by the comparison operators and evaluated to TRUE if the query returns no rows. |
ANY | ANY compares a value to each value in a list of results from a query and evaluates to true if the result of an inner query contains at least one row. |
BETWEEN | The SQL BETWEEN operator tests an expression against a range. The range consists of a beginning, followed by an AND keyword and an end expression. |
IN | The IN operator checks a value within a set of values separated by commas and retrieves the rows from the table that match. |
EXISTS | The EXISTS checks the existence of a result of a subquery. The EXISTS subquery tests whether a subquery fetches at least one row. When no data is returned then this operator returns 'FALSE'. |
SOME | SOME operator evaluates the condition between the outer and inner tables and evaluates to true if the final result returns any one row. If not, then it evaluates to false. |
UNIQUE | The UNIQUE operator searches every unique row of a specified table. |
Example: Special Operator (BETWEEN)
In this example, we will retrieve all records from the "employee" table where the "emp_id" column has a value that falls within the range of 101 to 104 (inclusive).
Query:
SELECT * FROM employee WHERE emp_id BETWEEN 101 AND 104;
Output:
Similar Reads
SQL Tutorial Structured Query Language (SQL) is the standard language used to interact with relational databases. Whether you want to create, delete, update or read data, SQL provides the structure and commands to perform these operations. SQL is widely supported across various database systems like MySQL, Oracl
8 min read
Basics
What is SQL?SQL was invented in the 1970s by IBM and was first commercially distributed by Oracle. The original name was SEQUEL (Structured English Query Language), later shortened to SQL. It is a standardized programming language used to manage, manipulate and interact with relational databases. It allow users
9 min read
SQL Data TypesSQL Data Types are very important in relational databases. It ensures that data is stored efficiently and accurately. Data types define the type of value a column can hold, such as numbers, text, or dates. Understanding SQL Data Types is critical for database administrators, developers, and data ana
5 min read
SQL OperatorsSQL operators are important in DBMS as they allow us to manipulate and retrieve data efficiently. Operators in SQL perform arithmetic, logical, comparison, bitwise, and other operations to work with database values. Understanding SQL operators is crucial for performing complex data manipulations, ca
5 min read
SQL Commands | DDL, DQL, DML, DCL and TCL CommandsSQL commands are crucial for managing databases effectively. These commands are divided into categories such as Data Definition Language (DDL), Data Manipulation Language (DML), Data Control Language (DCL), Data Query Language (DQL), and Transaction Control Language (TCL). In this article, we will e
7 min read
SQL Database OperationsSQL databases or relational databases are widely used for storing, managing and organizing structured data in a tabular format. These databases store data in tables consisting of rows and columns. SQL is the standard programming language used to interact with these databases. It enables users to cre
3 min read
SQL CREATE TABLEIn SQL, creating a table is one of the most essential tasks for structuring your database. The CREATE TABLE statement defines the structure of the database table, specifying column names, data types, and constraints such as PRIMARY KEY, NOT NULL, and CHECK. Mastering this statement is fundamental to
5 min read
Queries & Operations
SQL SELECT QueryThe SQL SELECT query is one of the most frequently used commands to retrieve data from a database. It allows users to access and extract specific records based on defined conditions, making it an essential tool for data management and analysis. In this article, we will learn about SQL SELECT stateme
4 min read
SQL INSERT INTO StatementThe SQL INSERT INTO statement is one of the most essential commands for adding new data into a database table. Whether you are working with customer records, product details or user information, understanding and mastering this command is important for effective database management. How SQL INSERT I
6 min read
SQL UPDATE StatementIn SQL, the UPDATE statement is used to modify existing records in a table. Whether you are updating a single record or multiple records at once, SQL provides the necessary functionality to make these changes. Whether you are working with a small dataset or handling large-scale databases, the UPDATE
6 min read
SQL DELETE StatementThe SQL DELETE statement is an essential command in SQL used to remove one or more rows from a database table. Unlike the DROP statement, which removes the entire table, the DELETE statement removes data (rows) from the table retaining only the table structure, constraints, and schema. Whether you n
4 min read
SQL | WHERE ClauseThe SQL WHERE clause allows filtering of records in queries. Whether you are retrieving data, updating records, or deleting entries from a database, the WHERE clause plays an important role in defining which rows will be affected by the query. Without WHERE clause, SQL queries would return all rows
4 min read
SQL | AliasesIn SQL, aliases are temporary names assigned to columns or tables for the duration of a query. They make the query more readable, especially when dealing with complex queries or large datasets. Aliases help simplify long column names, improve query clarity, and are particularly useful in queries inv
4 min read
SQL Joins & Functions
SQL Joins (Inner, Left, Right and Full Join)SQL joins are fundamental tools for combining data from multiple tables in relational databases. Joins allow efficient data retrieval, which is essential for generating meaningful observations and solving complex business queries. Understanding SQL join types, such as INNER JOIN, LEFT JOIN, RIGHT JO
5 min read
SQL CROSS JOINIn SQL, the CROSS JOIN is a unique join operation that returns the Cartesian product of two or more tables. This means it matches each row from the left table with every row from the right table, resulting in a combination of all possible pairs of records. In this article, we will learn the CROSS JO
3 min read
SQL | Date Functions (Set-1)SQL Date Functions are essential for managing and manipulating date and time values in SQL databases. They provide tools to perform operations such as calculating date differences, retrieving current dates and times and formatting dates. From tracking sales trends to calculating project deadlines, w
5 min read
SQL | String functionsSQL String Functions are powerful tools that allow us to manipulate, format, and extract specific parts of text data in our database. These functions are essential for tasks like cleaning up data, comparing strings, and combining text fields. Whether we're working with names, addresses, or any form
7 min read
Data Constraints & Aggregate Functions
SQL NOT NULL ConstraintIn SQL, constraints are used to enforce rules on data, ensuring the accuracy, consistency, and integrity of the data stored in a database. One of the most commonly used constraints is the NOT NULL constraint, which ensures that a column cannot have NULL values. This is important for maintaining data
3 min read
SQL PRIMARY KEY ConstraintThe PRIMARY KEY constraint in SQL is one of the most important constraints used to ensure data integrity in a database table. A primary key uniquely identifies each record in a table, preventing duplicate or NULL values in the specified column(s). Understanding how to properly implement and use the
5 min read
SQL Count() FunctionIn the world of SQL, data analysis often requires us to get counts of rows or unique values. The COUNT() function is a powerful tool that helps us perform this task. Whether we are counting all rows in a table, counting rows based on a specific condition, or even counting unique values, the COUNT()
7 min read
SQL SUM() FunctionThe SUM() function in SQL is one of the most commonly used aggregate functions. It allows us to calculate the total sum of a numeric column, making it essential for reporting and data analysis tasks. Whether we're working with sales data, financial figures, or any other numeric information, the SUM(
5 min read
SQL MAX() FunctionThe MAX() function in SQL is a powerful aggregate function used to retrieve the maximum (highest) value from a specified column in a table. It is commonly employed for analyzing data to identify the largest numeric value, the latest date, or other maximum values in various datasets. The MAX() functi
4 min read
AVG() Function in SQLSQL is an RDBMS system in which SQL functions become very essential to provide us with primary data insights. One of the most important functions is called AVG() and is particularly useful for the calculation of averages within datasets. In this, we will learn about the AVG() function, and its synta
4 min read
Advanced SQL Topics
SQL | SubqueryIn SQL, subqueries are one of the most powerful and flexible tools for writing efficient queries. A subquery is essentially a query nested within another query, allowing users to perform operations that depend on the results of another query. This makes it invaluable for tasks such as filtering, cal
6 min read
Window Functions in SQLSQL window functions are essential for advanced data analysis and database management. It is a type of function that allows us to perform calculations across a specific set of rows related to the current row. These calculations happen within a defined window of data and they are particularly useful
6 min read
SQL Stored ProceduresStored procedures are precompiled SQL statements that are stored in the database and can be executed as a single unit. SQL Stored Procedures are a powerful feature in database management systems (DBMS) that allow developers to encapsulate SQL code and business logic. When executed, they can accept i
7 min read
SQL TriggersSQL triggers are essential in database management systems (DBMS). They enable SQL statements to run when specific database events occur such as when someone adds, changes, or removes data. Triggers are commonly used to maintain data integrity, track changes, and apply business rules automatically, w
7 min read
SQL Performance TuningSQL performance tuning is an essential aspect of database management that helps improve the efficiency of SQL queries and ensures that database systems run smoothly. Properly tuned queries execute faster, reducing response times and minimizing the load on the serverIn this article, we'll discuss var
8 min read
SQL TRANSACTIONSSQL transactions are essential for ensuring data integrity and consistency in relational databases. Transactions allow for a group of SQL operations to be executed as a single unit, ensuring that either all the operations succeed or none of them do. Transactions allow us to group SQL operations into
8 min read
Database Design & Security
Introduction of ER ModelThe Entity-Relationship Model (ER Model) is a conceptual model for designing a databases. This model represents the logical structure of a database, including entities, their attributes and relationships between them. Entity: An objects that is stored as data such as Student, Course or Company.Attri
10 min read
Introduction of Database NormalizationNormalization is an important process in database design that helps improve the database's efficiency, consistency, and accuracy. It makes it easier to manage and maintain the data and ensures that the database is adaptable to changing business needs.Database normalization is the process of organizi
8 min read
SQL InjectionSQL Injection is a security flaw in web applications where attackers insert harmful SQL code through user inputs. This can allow them to access sensitive data, change database contents or even take control of the system. It's important to know about SQL Injection to keep web applications secure.In t
7 min read
SQL Data EncryptionIn todayâs digital era, data security is more critical than ever, especially for organizations storing the personal details of their customers in their database. SQL Data Encryption aims to safeguard unauthorized access to data, ensuring that even if a breach occurs, the information remains unreadab
5 min read
SQL BackupIn SQL Server, a backup, or data backup is a copy of computer data that is created and stored in a different location so that it can be used to recover the original in the event of a data loss. To create a full database backup, the below methods could be used : 1. Using the SQL Server Management Stu
4 min read
What is Object-Relational Mapping (ORM) in DBMS?Object-relational mapping (ORM) is a key concept in the field of Database Management Systems (DBMS), addressing the bridge between the object-oriented programming approach and relational databases. ORM is critical in data interaction simplification, code optimization, and smooth blending of applicat
7 min read