DDL Statements: CREATE, ALTER, DROP ----- Data Definition Language
DML statement: update, insert, delete, select ----- data manipulation language
DCL statement: is the database control function. ----- Statements used by the data control language
to set or change database user or role permissions, including (grant, deny, revoke, etc.) statements
Start mysql: ./mysql -uroot -p123456
quit: quit
Add the environment variable: vi /etc/profile -> Then add a sentence at the bottom: export PATH=/opt/lampp/bin:$PATH -> :wq save and exit -> source /etc/profile is it takes effect
Convenient entry: alias my='mysql -uroot -p123456' ---- After setting, enter my to enter mysql