Create duplicate & backup of table in SQL queries

Use of CTAS for creating the Duplicate table with data or only structure (by using where 1 = 0) in four main RDBMS database as follows:

SQL Server

-- Create structure with completed data
Select * into backup_employee from employees;

-- Create only structure of table
select * into backup_table from employees where 1=0;


Oracle

-- Create backup table with data
Create table backup_employee as select * from employees;

-- Create table with only structure
Create table backup_employee as select * from employees where 1=0;


MySQL

-- Create structure only
CREATE TABLE employees_new LIKE employees;

--Insert data into backup table
INSERT employees_new SELECT * FROM employees;


POSTGRESQL

-- create replica of table for backup
CREATE TABLE employees_new AS SELECT * FROM employees;

-- Create only structure
CREATE TABLE employees_new AS SELECT * FROM employees where 1=0;