Chapter 3, Problem 3.13RQ

Program Plan Intro

SQL:

• SQL stands for “Structured Query Language”.
• The current version of SQL is “ANSI SQL – 92”.
• It contains constructs which are used to define and process database. They are executed using DBMS-supplied command prompt.
• SQL is not a programming language. It is text-based and it is also called as data sublanguage. In order to get SQL as a complete programming language, it should be included in scripting languages like Java, C#, and so on.

DROP TABLE statement:

“DROP TABLE” statement comes under Data Definition Language. It is used to delete the information and to delete the structure of the table. The syntax to drop a table is as follows.

Syntax:

DROP TABLE table_Name;

ALTER TABLE Statement:

“ALTER TABLE” statement comes under Data Definition Language. It is used to modify column, add constraints, add column(s), drop column, rename column name and table name, drop constraints, and so on.

Syntax:

Syntax to drop constraint is as follows:

ALTER TABLE table_Name DROP CONSTRAINT constraintName;