SELECT INTO 和 INSERT INTO SELECT

一：SELECT INTO FROM语句
语句形式为：SELECT vale1, value2 into Table2 from Table1
前提表Table2不存在，因为在插入时会自动创建表Table2，并将Table1中指定字段数据复制到Table2中
--①.创建表UserInfo
    create TABLE UserInfo
    (
        u_id int,
        u_name varchar(10),
        u_pwd varchar(10),
        CONSTRAINT [PK_UserInfo] PRIMARY KEY CLUSTERED
        (
            u_id ASC
        )
    ) ON [PRIMARY]
    GO

--②.新建测试数据
    Insert into UserInfo values(1,'aa','show')
    Insert into UserInfo values(2,'bb','ming')
    Insert into UserInfo values(3,'cc','geng')
    Insert into UserInfo values(4,'dd','fan')
    GO

--③.SELECT INTO FROM语句创建表UserInfo2并复制数据
    select u_id,u_name,u_pwd INTO UserInfo2 from UserInfo
    GO

--④.查询更新后的结果
    select * from UserInfo
    select * from UserInfo2
    GO
二：INSERT INTO SELECT
语句形式为：Insert into Table2(field1,field2,...) select value1,value2,... from Table1
前提表Table2必须存在

--1.创建测试表
    create TABLE stuInfo
    (
        u_id int,
        u_name varchar(10),
        u_pwd varchar(10),
        CONSTRAINT [PK_stuInfo] PRIMARY KEY CLUSTERED
        (
            u_id ASC
        )
    ) ON [PRIMARY]
    GO
   create TABLE stuInfo2
    (
        u_id int,
        u_name varchar(10),
        u_pwd varchar(10),
        CONSTRAINT [PK_stuInfo2] PRIMARY KEY CLUSTERED
        (
            u_id ASC
        )
    ) ON [PRIMARY]
    GO
    --2.创建测试数据
      Insert into stuInfo values(1,'aa','show')
      Insert into stuInfo values(2,'bb','ming')
      Insert into stuInfo values(3,'cc','geng')
      Insert into stuInfo values(4,'dd','fan')
    GO
    --3.INSERT INTO SELECT语句复制表数据
    Insert into stuInfo2(u_id, u_name, u_pwd) select u_id, u_name,     u_pwd from stuInfo