- supported by all major commercial database systems
- standardized
- interactive via GUI or prompt, or embedded in programs
- declarative, based on relational algebra
Data Definition Language (DDL)
commands to create a table, drop tables, etc.
Data Manipulation Language (DML)
SELECT, INSERT, DELETE, UPDATE
Other commands: indexes, constraints, views, triggers, transactions, authorization…
SELECT statement
3 basic clauses: Select (3), From (1), Where (2)
result of SELECT is a relation