CREATE TABLE Statement in Oracle SQL – PLSQL Using Already Existing Tables

The CREATE TABLE statement in SQL allows us to create or define a new table in our database. It is a Data Definition Language (DDL) statement.

Here we will learn how to use CREATE TABLE statement to create new tables using already existing tables in the database.

Syntax for using CREATE TABLE statement to create a new table by already existing table(s) is:

CREATE TABLE new_table_name
AS
(SELECT *
FROM
old_table_name
);

Let’s take an example for understanding:

Suppose we already have a table named “Employee” as shown below.

Scenario 1:

We want to create a new table named “employee_copy” which should be copy of “Employee” table. For this we need to write the CREATE TABLE statement as follows.

CREATE TABLE employee_copy
AS
(SELECT *
FROM employee);

The above CREATE TABLE statement will create a new table named as employee_copy in the data base having 5 columns as ‘employee_id’,’employee_name’,’salary’,’department’ and ‘commission’. Also all the data from the employee table is copied to the employee_copy table.

If you query employee_copy table as,

SELECT *
FROM employee_copy;

You will get the following result.

Scenario 2:

We want to create a new table named “employee_copy” which should be contain only 3 columns of “Employee” table e.g(employee_id, employee_name and salary) . For this we need to write the CREATE TABLE statement as follows.

CREATE TABLE employee_copy
AS
(SELECT employee_id
        ,employee_name
        ,salary
 FROM employee);

The above CREATE TABLE statement will create a new table named as employee_copy in the database having 3 columns as ‘employee_id’,’employee_name’ and ’salary’ from employee table. Also all the data from the employee table of the aforementioned 3 columns will be copied to the employee_copy table.

If you query employee_copy table as,

SELECT *
FROM employee_copy;

You will get the following result:

Scenario 3:

Suppose we also have a department table in our database which has the list of departments as shown below:

And we want to create a new table named “employee_copy” which should be contain only 3 columns of “Employee” table e.g(employee_id, employee_name and salary) and 1 column from the “Department” table e.g. (department). For this we need to write the CREATE TABLE statement as follows.

CREATE TABLE employee_copy
AS
(SELECT employee_id
        ,employee_name
        ,salary
        ,dept.department
 FROM employee emp
      ,department dept
 WHERE emp.department = dept.department);

The above CREATE TABLE statement will create a new table named as employee_copy in the database having 4 columns as ‘employee_id’,’employee_name’ and ’salary’ from employee table and ‘department’ from department table.

The employee_copy table will have the data as shown below: