Fetching Data in PostgreSQL (SELECT Query) 🚀

The SELECT statement is used to retrieve data from PostgreSQL tables.

1. Basic Syntax

SELECT column1, column2 FROM table_name;

To fetch all columns, use:

SELECT * FROM table_name;

2. Fetch All Rows

SELECT * FROM users;

(Returns all columns and rows from the users table)

3. Fetch Specific Columns

SELECT name, email FROM users;

(Only returns name and email columns)

4. Fetch Data with Filtering (WHERE)

SELECT * FROM users WHERE age > 25;

(Returns users older than 25)

SELECT * FROM users WHERE email = 'alice@example.com';

(Returns only the user with email "alice@example.com")

5. Fetch Data with Sorting (ORDER BY)

SELECT * FROM users ORDER BY age DESC;

(Sorts users by age in descending order)

SELECT * FROM users ORDER BY name ASC;

(Sorts users alphabetically)

6. Fetch Limited Number of Rows (LIMIT)

SELECT * FROM users LIMIT 5;

(Only returns the first 5 rows)

SELECT * FROM users ORDER BY age DESC LIMIT 3;

(Returns the 3 oldest users)

7. Fetch Data with Offset (LIMIT OFFSET)

SELECT * FROM users ORDER BY id LIMIT 5 OFFSET 10;

(Skips the first 10 rows and fetches the next 5)