【轉】把一個表的數據插入到另一個表:INSERT INTO SELECT / SELECT INTO

原文鏈接：http://www.it118.org/Specials/c9fba99e-4401-49cf-8256-ac3c1a34c0d9/cf2a7ceb-1815-43fe-8810-47af11ac65a9.htm

有兩種方法可以是實現,而且不使用游標.下面兩種方法性能遠好於游標.

1.INSERT INTO SELECT
這種方法常用在目標表已經存在數據庫中.需要從源表把數據插入到目標表的情況.如果目標表和源表的列相同,就不必列出數據列了.

USE AdventureWorks 
GO 
----Create TestTable 
CREATE TABLE TestTable (FirstName VARCHAR(100), LastName VARCHAR(100)) 
----INSERT INTO TestTable using SELECT 
INSERT INTO TestTable (FirstName, LastName) 
SELECT FirstName, LastName 
FROM Person.Contact 
WHERE EmailPromotion = 2 
----Verify that Data in TestTable 
SELECT FirstName, LastName 
FROM TestTable 
----Clean Up Database 
DROP TABLE TestTable 
GO 
USE AdventureWorks 
GO 
----Create TestTable 
CREATE TABLE TestTable (FirstName VARCHAR(100), LastName VARCHAR(100)) 
----INSERT INTO TestTable using SELECT 
INSERT INTO TestTable --(FirstName, LastName) 
SELECT FirstName, LastName 
FROM Person.Contact 
WHERE EmailPromotion = 2 
----Verify that Data in TestTable 
SELECT FirstName, LastName 
FROM TestTable 
----Clean Up Database 
DROP TABLE TestTable 
GO 

仔細看看有什么區別.

2.SELECT INTO
這種方法用在目標表事先不存在於數據庫.在插入數據的同時新建表.新表的字段名和數據類型和需要插入的列相同.

USE AdventureWorks 
GO 
----Create new table and insert into table using SELECT INSERT 
SELECT FirstName, LastName 
INTO TestTable 
FROM Person.Contact 
WHERE EmailPromotion = 2 
----Verify that Data in TestTable 
SELECT FirstName, LastName 
FROM TestTable 
----Clean Up Database 
DROP TABLE TestTable 
GO 

我也常用它來復制數據結構,但不插入數據.

USE AdventureWorks 
GO 
----Create new table and insert into table using SELECT INSERT 
SELECT FirstName, LastName 
INTO TestTable 
FROM Person.Contact 
WHERE 1=2 
DROP TABLE TestTable 
GO