SQL

Basic Commands#

MySQL#

Start MySQL Service#

sudo systemctl start mysqlbash

Secure MySQL Installation#

sudo mysql_secure_installationbash

Login to MySQL#

mysql -u root -pbash

Create a Database#

CREATE DATABASE database_name;sql

Create a User#

CREATE USER 'username'@'localhost' IDENTIFIED BY 'password';sql

Grant Privileges#

GRANT ALL PRIVILEGES ON database_name.* TO 'username'@'localhost';
FLUSH PRIVILEGES;sql

PostgreSQL#

Start PostgreSQL Service#

sudo systemctl start postgresqlbash

Login to PostgreSQL#

sudo -i -u postgres
psqlbash

Create a Database#

CREATE DATABASE database_name;sql

Create a User#

CREATE USER username WITH PASSWORD 'password';sql

Grant Privileges#

GRANT ALL PRIVILEGES ON DATABASE database_name TO username;sql

Basic SQL Commands#

Select Data#

SELECT * FROM table_name;
SELECT column1, column2 FROM table_name;sql

Insert Data#

INSERT INTO table_name (column1, column2) VALUES (value1, value2);sql

Update Data#

UPDATE table_name SET column1 = value1, column2 = value2 WHERE condition;sql

Delete Data#

DELETE FROM table_name WHERE condition;sql