INSERT INTO SELECT語句與SELECT INTO FROM語句的一些區(qū)別

2024-08-31 00:44:59

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1.INSERT INTO SELECT語句
語句形式為：Insert into Table2(field1,field2,...) select value1,value2,... from Table1

要求目標表Table2必須存在，由于目標表Table2已經(jīng)存在，所以我們除了插入源表Table1的字段外，還可以插入常量。示例如下：

INSERT INTO SELECT語句復制表數(shù)據(jù)

復制代碼代碼如下:

--1.創(chuàng)建測試表
create TABLE Table1
(
a varchar(10),
b varchar(10),
c varchar(10),
CONSTRAINT [PK_Table1] PRIMARY KEY CLUSTERED
(
a ASC
)
) ON [PRIMARY]

create TABLE Table2
(
a varchar(10),
c varchar(10),
d int,
CONSTRAINT [PK_Table2] PRIMARY KEY CLUSTERED
(
a ASC
)
) ON [PRIMARY]
GO
--2.創(chuàng)建測試數(shù)據(jù)
Insert into Table1 values('趙','asds','90')
Insert into Table1 values('錢','asds','100')
Insert into Table1 values('孫','asds','80')
Insert into Table1 values('李','asds',null)
GO
select * from Table2

--3.INSERT INTO SELECT語句復制表數(shù)據(jù)
Insert into Table2(a, c, d) select a,c,5 from Table1
GO

--4.顯示更新后的結(jié)果
select * from Table2
GO
--5.刪除測試表
drop TABLE Table1
drop TABLE Table2

2.SELECT INTO FROM語句

語句形式為：SELECT vale1, value2 into Table2 from Table1

要求目標表Table2不存在，因為在插入時會自動創(chuàng)建表Table2，并將Table1中指定字段數(shù)據(jù)復制到Table2中。示例如下：

SELECT INTO FROM創(chuàng)建表并復制表數(shù)據(jù)

復制代碼代碼如下:

--1.創(chuàng)建測試表
create TABLE Table1
(
a varchar(10),
b varchar(10),
c varchar(10),
CONSTRAINT [PK_Table1] PRIMARY KEY CLUSTERED
(
a ASC
)
) ON [PRIMARY]
GO

--2.創(chuàng)建測試數(shù)據(jù)
Insert into Table1 values('趙','asds','90')
Insert into Table1 values('錢','asds','100')
Insert into Table1 values('孫','asds','80')
Insert into Table1 values('李','asds',null)
GO

--3.SELECT INTO FROM語句創(chuàng)建表Table2并復制數(shù)據(jù)
select a,c INTO Table2 from Table1
GO

--4.顯示更新后的結(jié)果
select * from Table2
GO
--5.刪除測試表
drop TABLE Table1
drop TABLE Table2