SQL Operators

Description

SQL operators are symbols or keywords used to perform operations on data. They can be classified into several categories.

Clauses: In SQL, clauses are typically complete statements within a query that define specific parts of its functionality. Examples include SELECT, FROM, WHERE, JOIN, etc. These clauses work together to form the overall query structure.

Operators: Operators are symbols or keywords that perform specific operations on data or expressions within a query. They typically combine values or manipulate data in some way.

Different Operators

Arithmetic Operators:

Used to perform mathematical operations.

• + (Addition)

• - (Subtraction)

• * (Multiplication)

• / (Division)

• % (Modulo)

Example:

SELECT salary + 1000 AS increased_salary FROM employees;

Comparison Operators:

Used to compare two values.

• = (Equal to)

• <> or != (Not equal to)

• > (Greater than)

• < (Less than)

• >= (Greater than or equal to)

• <= (Less than or equal to)

Example:

SELECT * FROM employees WHERE salary > 50000;

Logical Operators:

Used to combine multiple conditions.

• AND (Both conditions must be true)

• OR (At least one condition must be true)

• NOT (Negates a condition)

Example:

SELECT * FROM employees WHERE salary > 50000 AND department_id = 10;

Bitwise Operators:

Used to perform bitwise operations.

• & (Bitwise AND)

• | (Bitwise OR)

• ^ (Bitwise XOR)

Example:

SELECT 5 & 3;  -- Results in 1

Set Operators:

Used to combine the results of two or more queries.

• UNION (Combines results of two queries and removes duplicates)

• UNION ALL (Combines results of two queries without removing duplicates)

• INTERSECT (Returns common results of two queries)

• MINUS or EXCEPT (Returns results from the first query that are not in the second query)

Example:

SELECT name FROM employees
UNION
SELECT name FROM managers;

String Operators:

Used to perform operations on strings.

• || (Concatenation in Oracle and PostgreSQL)

• + (Concatenation in SQL Server)

• LIKE (Pattern matching)

Example:

SELECT first_name || ' ' || last_name AS full_name FROM employees;