Category: PostgreSQL Tutorial

PostgreSQL is an free open-source database system that supports both relational (SQL) and non-relational (JSON) queries.

PostgreSQL is a back-end database for dynamic websites and web applications.

PostgreSQL Tutorial

PostgreSQL DROP TABLE

PostgreSQL DROP TABLE (Beginner → Advanced) In PostgreSQL DROP TABLE is used to permanently delete a table from the database, including: all data (rows) table structure indexes constraints triggers This action is irreversible. What...

PostgreSQL Tutorial

PostgreSQL DELETE

PostgreSQL DELETE Statement (Beginner → Advanced) In PostgreSQL DELETE statement is used to remove rows (records) from a table.It is a DML command and is transaction-safe, meaning it can be rolled back. What is...

PostgreSQL Tutorial

PostgreSQL DROP COLUMN

PostgreSQL DROP COLUMN (Beginner → Advanced) In PostgreSQL DROP COLUMN is used to permanently remove a column from an existing table.This operation deletes the column and all its data. Irreversible – once dropped, the...

PostgreSQL Tutorial

PostgreSQL ALTER COLUMN

🧱 PostgreSQL ALTER COLUMN (Beginner → Advanced) In PostgreSQL ALTER COLUMN is used to modify an existing column’s definition—such as its data type, default value, nullability, or storage properties—without dropping the table. 1️⃣ What...

PostgreSQL Tutorial

PostgreSQL UPDATE

✏️ PostgreSQL UPDATE Statement (Beginner → Advanced) The UPDATE statement in PostgreSQL is used to modify existing records (rows) in a table.It is a DML command, transaction-safe, and very important for real projects &...

PostgreSQL Tutorial

PostgreSQL ADD COLUMN

PostgreSQL ADD COLUMN (Beginner → Advanced) The ADD COLUMN command in PostgreSQL is used to add a new column to an existing table without deleting existing data.It’s one of the most common schema-evolution operations....

PostgreSQL Tutorial

PostgreSQL Select Data

PostgreSQL Select Data (Beginner → Advanced) In PostgreSQL Select Data is used to retrieve (read) data from one or more tables.It is the most frequently used SQL command and the foundation of database querying. What...

PostgreSQL Tutorial

PostgreSQL Insert Data

PostgreSQL INSERT Data In PostgreSQL, the INSERT statement is used to add new records (rows) into a table.This is one of the most important SQL operations and is frequently asked in interviews. What is...

PostgreSQL Tutorial

PostgreSQL Create Table

PostgreSQL Create Table In PostgreSQL Create Table is used to store data in rows and columns. You create a table using the CREATE TABLE statement. Basic Syntax

CREATE TABLE table_name (
column1 datatype constraints,
column2 datatype constraints,
...
);

CREATE TABLE table_name (

column1 datatype constraints,

column2 datatype constraints,

...

);

Simple Create Table Example

CREATE TABLE users (
id SERIAL PRIMARY KEY,
name VARCHAR(100),
email VARCHAR(150),
age INT
);

CREATE TABLE users (

id SERIAL PRIMARY KEY,

name VARCHAR(100),

email VARCHAR(150),

age INT

);

Explanation: SERIAL...

PostgreSQL Tutorial

PostgreSQL pgAdmin 4

PostgreSQL pgAdmin 4 – Complete Guide pgAdmin 4 is the official graphical user interface (GUI) tool for managing PostgreSQL databases.It allows you to create databases, run SQL queries, manage tables, users, and view data...