Question

I’d like to refactor my database by splitting a single table into two. I’d like to moving a few existing columns to a new table. For instance, suppose I want to move the address field in the below Employee table to a new Address table.

How can I accomplish this using sqlite (or SQL if equivalent)?

Before:

Employee Table
   employee_id (Primary)
   name
   address
   city

After:

Employee Table
   employee_id (Primary)
   name
   address_id

Address Table
   address_id (Primary)
   address
   city

Answer 1

Try this:

  CREATE TABLE Employee(
  emp_id int,
  name nvarchar(50),
  address nvarchar(50),
  city nvarchar(50),
  PRIMARY KEY (emp_Id));

ALTER TABLE Employee
ADD address_id int NOT NULL IDENTITY;

INSERT INTO EMPLOYEE(emp_id,name,address,city) VALUES (111,'JOHN','XXX STREET','XYZ');

CREATE TABLE Address(
   address_id int NOT NULL,
   address nvarchar(100),
   city nvarchar(100),
   PRIMARY KEY (address_id)
  );

INSERT INTO Address (address_id, address, city)
SELECT address_id, address, city
FROM Employee;

ALTER TABLE Employee
DROP COLUMN address;

ALTER TABLE Employee
DROP COLUMN city;

Check here