ubuntu ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2) code example

Example 1: ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)

sudo chown -R _mysql:mysql /usr/local/var/mysql

sudo mysql.server start

Example 2: ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

# Remove mysql
sudo apt-get remove --purge mysql\*

#update repositories
sudo apt update

# Reinstall it
sudo apt install mysql-server mysql-client

# Test if it runs
sudo mysql

# You can install also thes pachages. Optionnaly
sudo apt install php

#mesabo youbeyou

Example 3: ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.s

> ln -s /var/lib/mysql/mysql.sock /tmp/mysql.sock
> 
> service mysql start or service mysql start