Which of the following is NOT a valid DDL command?
A.
UPDATE
B.
ALTER
C.
DROP
D.
CREATE
Explanation:
UPDATE is a DML command. Data-definition language (DDL) is used to specify a database schema by a set of
definitions. It is a computer
language for defining data structures. The term wasfirst introduced in relation to the Codasyl database model,
where the schema of the
database was written in a Data Definition Language describing the records, fields, and “sets” making up the
user Data Model. The term DDL is
used in a generic sense to refer to any formal language for describing data or information structures,like XML
schemas. CREATE, DROP, and
ALTER are the major DDL commands.
Answer C, B, and D are incorrect. DROP, ALTER, and CREATE are valid DDL commands.