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;