SQL CREATE TABLE

The CREATE TABLE Statement is used to create tables to store data. Integrity Constraints like primary key, unique key, foreign key can be defined for the columns while creating the table. The integrity constraints can be defined at column level or table level. The implementation and the syntax of the CREATE Statements differs for different RDBMS.

The Syntax for the CREATE TABLE Statement is:

CREATE TABLE table_name
(column_name1 datatype,
column_name2 datatype,
... column_nameN datatype
);

·         table_name - is the name of the table.

·         column_name1, column_name2.... - is the name of the columns

·         datatype - is the datatype for the column like char, date, number etc.

For Example: If you want to create the employee table, the statement would be like,

CREATE TABLE employee
( id number(5),
name char(20),
dept char(10),
age number(2),
salary number(10),
location char(10)
);

In Oracle database, the datatype for an integer column is represented as "number". In Sybase it is represented as "int".

Oracle provides another way of creating a table.

CREATE TABLE temp_employee
SELECT * FROM employee 

In the above statement, temp_employee table is created with the same number of columns and datatype as employee table.

-----------------------------------------------------------------------------------

The CREATE TABLE statement allows you to create and define a table.

The basic syntax for a CREATE TABLE statement is:

CREATE TABLE table_name
( column1 datatype null/not null,
  column2 datatype null/not null,
  ...
);

Each column must have a datatype. The column should either be defined as "null" or "not null" and if this value is left blank, the database assumes "null" as the default.

For example:

CREATE TABLE suppliers
(	supplier_id	number(10)	not null,
	supplier_name	varchar2(50)	not null,
	contact_name	varchar2(50)
);