Question

我想通过将一个表分成两个来重构我的数据库。我想将一些现有列移动到新表中。例如，假设我想将下面address表中的Employee字段移动到新的Address表。

如何使用sqlite （或等效的SQL）来完成？

之前：

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

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;

Answer 2

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 3

1：在第一个表格中创建AddressID列并指定一个数字 2：将新表空创建。
3：传输数据（类似这样）
插入地址（ADDRESS_ID，ADDRESS，CITY）
从员工中选择ADDRESS_ID，ADDRESS，CITY 4：从第一个表中删除旧列并创建外键

如何将列从一个表移动到新表？

3 个答案: