Chapter 3, Problem 1RQ

Program Plan Intro

SQL:

• SQL stands for “Structured Query Language”.
• The current version of SQL is “ANSI SQL – 92”.
• 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.
• It contains constructs which are used to define and process database. They are executed using DBMS-supplied command prompt.
• Some of the DBMS products that provides GUI tools in order to perform tasks are as follows:
  • SQL Server
  • Oracle Database
  • MySQL

Data Definition Language (DDL):

It is used for creating tables and other structures. They perform operations like creating tables, modifying database, and removing database.

Explanation of Solution

Table Creation:

Creating table comes under Data Definition Language (DDL).

• The “CREATE TABLE” command is used to create a table by specifying the table name and then by listing the column in a single set of parentheses in the table.
• The “CREATE” command is employed for establishing databases on our platform by constructing tables in an already existing database.

The Syntax for creating table is as follows:

CREATE TABLE TABLE_NAME (

  Column1 datatype,

  Column2 datatype,

);

Creating table “EMP”:

CREATE TABLE EMP (

EMP_NUM     CHAR(3)

EMP_LNAME      VARCHAR(15)

EMP_FNAME      VARCHAR(15)));

Explanation:

 The above query is used to create a table structure named “EMP” . The attribute “EMP_NUM” is declared as “CHAR” and the attributes “EMP_LNAME” and “EMP_FNAME” is declared as “VARCHAR”.