如何将一列中的列移动到新表中？

Question

我想通过将一个表拆分为两个来重构我的数据库。我想将一些现有的列移动到一个新表中。例如，假设我想将以下Employee表中的address字段移动到新的Address表中。

如何使用sqlite（或SQL，如果有的话）完成这个？

前：

Employee Table 
    employee_id (Primary) 
    name 
    address 
    city 

后：

Employee Table 
    employee_id (Primary) 
    name 
    address_id 

Address Table 
    address_id (Primary) 
    address 
    city 

Answer 1

试试这个：

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; 

检查here

Answer 2

1：创建您的第一个表中的列AddressID并分配一个号码。
2：创建新表为空。
3：传输数据（像这样）
INSERT INTO ADDRESS（ADDRESS_ID，地址，城市）
SELECT ADDRESS_ID，地址，城市FROM EMPLOYEE
4：从第一个表中删除旧列并创建外键

Answer 3

create table employee_new(employee_id,name,address_id); 
insert into employee_new select employee_id,name,employee_id from employee; 
create table address(address_id,address,city); 
insert into address select employee_id,address,city from employee; 
alter table employee rename to employee_old; 
alter table employee_new rename to employee;