SQL Create Table

SQL Create Table

 SQL Create statement allows you create database table

Syntax:

CREATE TABLE < table_name>

            (Col1 datatype1,

              Col2 datatype2 …coln datatypen);

Example:

CREATE TABLE Student

(

   no      NUMBER (2),

   name    VARCHAR (10),

   marks   NUMBER (3)

);

Create Table By Using Select Statement

We can create table by existing table or we call it is as copy of existing table by using select statement 

Syntax:

CREATE TABLE < New_table_name> AS

    SELECT  Col1,Col2 …Coln  WHERE ….;

Example:

By following example we can create table along with data.

CREATE TABLE student_copy AS

           SELECT  NO,

                     NAME,

                   MARKS

            FROM student;

Example:

By following example we can create table without data.

CREATE TABLE student_copy AS

           SELECT  NO,

                     NAME,

                   MARKS

            FROM student WHERE 1=2;

Create Table By Using Constrains

 Example:

 

CREATE TABLE emp

(

   empno       NUMBER PRIMARY KEY,

   ename       VARCHAR2 (50) NOT NULL,

   job         VARCHAR2 (10),

   mgr         NUMBER,

   hiredate    DATE DEFAULT (SYSDATE),

   sal         NUMBER,

   hrly_rate   NUMBER,

   comm        NUMBER,

   deptno      NUMBER NOT NULL 

);

Note: To know more about constrains >SQL Constraints