CREATE DATABASE: CREATE DATABASE salesdb CHARACTER SET utf8mb4; : Create new database with chosen charset

ALTER DATABASE: ALTER DATABASE salesdb COLLATE utf8mb4_0900_ai_ci; : Change database properties

DROP DATABASE: DROP DATABASE olddb; : Remove database and all contents

CREATE TABLE: CREATE TABLE emp(id INT PRIMARY KEY,name VARCHAR(50)); : Define structure to store data

CREATE TEMPORARY TABLE: CREATE TEMPORARY TABLE tmp SELECT * FROM emp LIMIT 0; : Create table that exists only for session

ALTER TABLE ADD: ALTER TABLE emp ADD COLUMN joined DATE; : Add new column to existing table

ALTER TABLE MODIFY: ALTER TABLE emp MODIFY COLUMN name VARCHAR(100); : Change column definition

ALTER TABLE DROP: ALTER TABLE emp DROP COLUMN obsolete; : Remove column

RENAME TABLE: RENAME TABLE temp TO archive_emp; : Change table name

DROP TABLE: DROP TABLE IF EXISTS junk; : Delete table permanently

CREATE VIEW: CREATE VIEW v_active AS SELECT * FROM users WHERE active=1; : Save query as virtual
table

ALTER VIEW: ALTER VIEW v_active AS SELECT id,name FROM users WHERE active=1; : Change view definition

DROP VIEW: DROP VIEW v_active; : Remove view

CREATE INDEX: CREATE INDEX idx_dept ON emp(dept); : Speed up queries filtering by column

CREATE UNIQUE INDEX: CREATE UNIQUE INDEX uidx_email ON users(email); : Enforce uniqueness and
speed lookup

DROP INDEX: DROP INDEX idx_dept ON emp; : Remove index

FULLTEXT INDEX: CREATE FULLTEXT INDEX f_idx ON docs(content); : Enable full text search on text columns

SPATIAL INDEX: CREATE SPATIAL INDEX s_idx ON geom(geo); : Accelerate spatial queries on geometry

CREATE SEQUENCE: CREATE SEQUENCE seq START WITH 1 INCREMENT BY 1; : Generate sequential numbers (MariaDB/Postgres)

AUTO_INCREMENT: id INT AUTO_INCREMENT PRIMARY KEY; : Automatically assign incrementing IDs