Friday, December 21, 2012

SQL CREATE TABLE Statement

SQL CREATE TABLE Statement

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.

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Thank you :
- kareem