DEV Community

Shikha Gupta
Shikha Gupta

Posted on

SQL Operators Made Easy for Beginners

SQL Operators Made Easy for Beginners

SQL (Structured Query Language) uses operators to perform operations on data. Here’s a simple guide to understand the basics:

  1. Arithmetic Operators These are used for mathematical operations.
  • + (Addition): Adds two numbers.
  SELECT 3 + 2; -- Result is 5
Enter fullscreen mode Exit fullscreen mode
  • - (Subtraction): Subtracts one number from another.
  SELECT 5 - 3; -- Result is 2
Enter fullscreen mode Exit fullscreen mode
  • (Multiplication): Multiplies two numbers. sql SELECT 4 2; -- Result is 8 ``
  • / (Division): Divides one number by another. `sql SELECT 10 / 2; -- Result is 5 `
  • % (Modulus): Returns the remainder of a division. `sql SELECT 10 % 3; -- Result is 1 `
  1. Comparison Operators These are used to compare two values.
  • = (Equal): Checks if two values are equal. `sql SELECT FROM employees WHERE salary = 50000; `
  • != or <> (Not Equal): Checks if two values are not equal. `sql SELECT FROM employees WHERE department != 'HR'; `
  • > (Greater Than): Checks if the left value is greater than the right value. `sql SELECT FROM employees WHERE age > 30; `
  • < (Less Than): Checks if the left value is less than the right value. `sql SELECT FROM employees WHERE age < 25; `
  • >= (Greater Than or Equal To): Checks if the left value is greater than or equal to the right value. `sql SELECT FROM employees WHERE experience >= 5; `
  • <= (Less Than or Equal To): Checks if the left value is less than or equal to the right value. `sql SELECT FROM employees WHERE experience <= 2; `
  1. Logical Operators These are used to combine multiple conditions.
  • AND: Combines two or more conditions. All conditions must be true. `sql SELECT FROM employees WHERE age > 25 AND department = 'Finance'; `
  • OR: Combines two or more conditions. At least one condition must be true. `sql SELECT FROM employees WHERE age < 30 OR department = 'HR'; `
  • NOT: Reverses the result of a condition. `sql SELECT FROM employees WHERE NOT (age < 30); `
  1. Between and In Operators
  • BETWEEN: Selects values within a given range (inclusive). `sql SELECT FROM employees WHERE salary BETWEEN 30000 AND 50000; `
  • IN: Checks if a value is within a set of values. `sql SELECT FROM employees WHERE department IN ('HR', 'Finance', 'IT'); `
  1. LIKE and IS NULL Operators
  • LIKE: Used for pattern matching. % represents zero or more characters, _ represents a single character. `sql SELECT FROM employees WHERE name LIKE 'J%'; -- Names starting with 'J' SELECT FROM employees WHERE name LIKE '_

https://www.youtube.com/watch?v=3tCym9ZkEdk&t=3s

Billboard image

The Next Generation Developer Platform

Coherence is the first Platform-as-a-Service you can control. Unlike "black-box" platforms that are opinionated about the infra you can deploy, Coherence is powered by CNC, the open-source IaC framework, which offers limitless customization.

Learn more

Top comments (0)

A Workflow Copilot. Tailored to You.

Pieces.app image

Our desktop app, with its intelligent copilot, streamlines coding by generating snippets, extracting code from screenshots, and accelerating problem-solving.

Read the docs

πŸ‘‹ Kindness is contagious

Discover a treasure trove of wisdom within this insightful piece, highly respected in the nurturing DEV Community enviroment. Developers, whether novice or expert, are encouraged to participate and add to our shared knowledge basin.

A simple "thank you" can illuminate someone's day. Express your appreciation in the comments section!

On DEV, sharing ideas smoothens our journey and strengthens our community ties. Learn something useful? Offering a quick thanks to the author is deeply appreciated.

Okay