SQL (Structured Query Language) is a special-purpose programming
language designed for managing data held in a relational database management
system (RDBMS). It is designed based on relational algebra (Set theorem,
Joins).
SQL consists of a data definition
language(DDL), data manipulation
language(DML), and Data Control
Language(DCL).
The Data Definition Language (DDL) manages table and index structure in
database. The most basic items of DDL are the CREATE, ALTER, RENAME, DROP and
TRUNCATE statements.
The Data Manipulation Language (DML) manages add, update and delete
data in database.
The Data Control Language (DCL) authorizes users to access and manipulate
data. Its two main statements GRANT and REVOKE.
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