有两张表:
临时表:table1
正式表:table2
table1,table2表结构相同,有以下几列:
{
a1 varchar(50),主键
a2 varchar(50),主键
a3 varchar(50),主键
a4 bigint(8),
a5 varchar(50)}
以前表中a1,a2两列是主键,现在又增加了一列a3作为主键问题:把数据从table1 导入到table2中,
要求:如果table1中的a1,a2,a3三列和table2中的a1,a2,a3三列不全相同,做Insert操作,否则:Update a4,a5二列值。
现在我做转档的时候,提示在table2中不能插入重复主键???不知道什么原因?????急!!!!!!
临时表:table1
正式表:table2
table1,table2表结构相同,有以下几列:
{
a1 varchar(50),主键
a2 varchar(50),主键
a3 varchar(50),主键
a4 bigint(8),
a5 varchar(50)}
以前表中a1,a2两列是主键,现在又增加了一列a3作为主键问题:把数据从table1 导入到table2中,
要求:如果table1中的a1,a2,a3三列和table2中的a1,a2,a3三列不全相同,做Insert操作,否则:Update a4,a5二列值。
现在我做转档的时候,提示在table2中不能插入重复主键???不知道什么原因?????急!!!!!!
如果是sql 2000,2005得分两步.
1.
update tb2
set a4 = tb1.a4, a5 = tb1.a5
from tb2 , tb1
where tb2.a1 = tb1.a1 and tb2.a2 = tb1.a2 and tb2.a3 = tb1.a32.
insert into tb2 select * from tb1 where not exists(select 1 from tb1 where tb2.a1 = tb1.a1 and tb2.a2 = tb1.a2 and tb2.a3 = tb1.a3)
using [source] s on t.id = s.id
when matched then update t.name = s.name, t.age = s.age -- use "rowset1"
when not matched then insert values(id,name,age) -- use "rowset2"
when source not matched then delete; -- use "rowset3" 如你所见,具体操作是根据后面的联合(join)的解析结果来确定的。在这个例子中,如果目标和源数据表有匹配的行,就实行更新操作。如果没有,就实行插入或者删除操作来使目标数据表和源数据表保持一致。 这个新句法的一个美妙之处是它在处理更新时的确定性。在使用标准的UPDATE句法和联合时,可能有超过一个源行跟目标行匹配。在这种情况下,无法预料更新操作会采用哪个源行的数据。 而当使用MERGE句法时,如果存在多处匹配,它会抛出一个错误。这就提醒了开发者,要达到预想的目标,当前的联合条件还不够明确。 SQL Server 2008 MERGE
ZDNet 软件频道 更新时间:2007-11-19 作者:David.Portas 来源:David Portas’ Blog
本文关键词:MERGE SQL Server 2008 SQL Server 数据库
MERGE is a new DML statement in SQL Server 2008. Microsoft have implemented the ISO SQL 2003 and 2007 standard MERGE statement (as seen in Oracle and DB2) and added some extensions of their own.In a nutshell, MERGE allows you to perform simultaneous UPDATE, INSERT and/or DELETE operations on one table. There are new physical operators that combine these operations so that they can be performed in a single scan rather than multiple scans.MERGE has loads of possible applications. For the first time you can assign the contents of one table or query to another in a single operation. The following example requires SQL Server 2008 CTP4. Given this schema and data:CREATE TABLE a
(keycol INT PRIMARY KEY,
col1 INT NOT NULL,
col2 INT NOT NULL,
col3 INT NOT NULL);CREATE TABLE b
(keycol INT PRIMARY KEY,
col1 INT NOT NULL,
col2 INT NOT NULL,
col3 INT NOT NULL);INSERT INTO a VALUES (1,0,0,0),(2,0,0,0);
INSERT INTO b VALUES (1,1,1,1),(3,3,3,3);The following MERGE will populate table a with the same data as table b:MERGE INTO a
USING b
ON a.keycol = b.keycol
WHEN MATCHED THEN
UPDATE SET
col1 = b.col1,
col2 = b.col2,
col3 = b.col3
WHEN NOT MATCHED THEN
INSERT (keycol, col1, col2, col3)
VALUES (b.keycol, b.col1, b.col2, b.col3)
WHEN SOURCE NOT MATCHED THEN
DELETE;In the relational world this is the operation known as Relational Assignment ie: a := bUnfortunately the SQL syntax is less pretty and requires just a little more typing!MERGE also makes a good "upsert" for application CRUD stored procedures, removing the need for constructs like:IF NOT EXISTS ...
INSERT ...Here's an example I created today. It inserts a new Vendor if and only if the name doesn't already exist. Whether the name previously existed or not, it returns the IDENTITY value of the existing or newly inserted row.CREATE PROC dbo.usp_VendorUpsert( @pVendorID INT OUTPUT, @pVendorName VARCHAR(80)) ASBEGIN SET NOCOUNT ON; MERGE dbo.Vendor t USING (SELECT @pVendorName ) p(VendorName) ON t.VendorName = @pVendorName WHEN NOT MATCHED THEN INSERT (VendorName) VALUES (@pVendorName) WHEN MATCHED THEN UPDATE SET @pVendorID = VendorID; SET @pVendorID = COALESCE(SCOPE_IDENTITY(),@pVendorID); END RETURN It's amazing that it took nearly 20 years for the SQL standards committee to come up with MERGE. Perhaps the delay is a legacy of the decision to make INSERT, UPDATE and DELETE the basic data update operators. INSERT, UPDATE and DELETE can all be defined as different kinds of relational assignment - assignment being the most basic type of update possible. So arguably MERGE is the more primitive and fundamental data update operator that ought to have been around earlier rather than later.
select * from table1
where table1.a1<> table2.a1 and table1.a2<> table2.a2 and table1.a2<> table2.a2
Declare @a1 varchar(50)
Declare @c2 varchar(50)
Declare @a3 varchar(50)
Declare copy_cur Cursor for
Select a1,a2,a3 From table1
Open copy_cur
Fetch Next From copy_cur into @a1,@a2,,@a3
WHILE @@FETCH_STATUS = 0
Begin
if exists(Select * From table2 where a1=@a1 and a2=@a2 and a3=@a3)
begin
update b
set b.a4=a.a4,b.a5=a.a5
from table1 a,table2 b
where a.a1=b.a1 and a.a2=b.a2 and a.a3=b.a3 and b.a1=@a1 and b.a2=@a2 and b.a3=@a3
end
else
begin
insert into table2
select * From table1 where a1=@a1 and a2=@a2 and a3=@a3
end
Fetch Next From copy_cur into @a1,@a2,,@a3
End;
Close copy_cur
Deallocate copy_cur
是不是和这个有关系呢,a3是我新增加的列又把它做为其中的一个联合主键之一,默认值设为了'0'我写的Insert 部分SQL如下:insert into tb2(a1,a2,a3,a4,a5)
select tb1.a1,tb1.a2,tb1.a3,tb1.a4,tb1.a5 from tb1,tb2 where (tb2.a1 <> tb1.a1 and tb2.a2 <> tb1.a2 and tb2.a3 <> tb1.a3)
insert into tb2(a1,a2,a3,a4,a5)
select tb1.a1,tb1.a2,tb1.a3,tb1.a4,tb1.a5 from tb1 where not exists(select 1 from tb2 where tb2.a1 = tb1.a1 and tb2.a2 = tb1.a2 and tb2.a3 = tb1.a3)
select tb1.a1,tb1.a2,tb1.a3,tb1.a4,tb1.a5 from tb1 where not exists(select 1 from tb2 where tb2.a1 = tb1.a1 and tb2.a2 = tb1.a2 and tb2.a3 = tb1.a3)
insert into tb2(a1,a2,a3,a4,a5)
select tb1.a1,tb1.a2,tb1.a3,tb1.a4,tb1.a5 from tb1 where not exists(select 1 from tb2 where isnull(tb2.a1,0) = isnull(tb1.a1,0) and isnull(tb2.a2,0) = isnull(tb1.a2,0) and isnull(tb2.a3,0) = isnull(tb1.a3,0))
--如果列是字符的话
insert into tb2(a1,a2,a3,a4,a5)
select tb1.a1,tb1.a2,tb1.a3,tb1.a4,tb1.a5 from tb1 where not exists(select 1 from tb2 where isnull(tb2.a1,'') = isnull(tb1.a1,'') and isnull(tb2.a2,'') = isnull(tb1.a2,'') and isnull(tb2.a3,'') = isnull(tb1.a3,''))
insert into tb2(a1,a2,a3,a4,a5)
select tb1.a1,tb1.a2,tb1.a3,tb1.a4,tb1.a5 from tb1 where not exists(select 1 from tb2 where isnull(tb2.a1,'') = isnull(tb1.a1,'') and isnull(tb2.a2,'') = isnull(tb1.a2,'') and isnull(tb2.a3,'') = isnull(tb1.a3,''))
select tb1.a1,tb1.a2,tb1.a3,tb1.a4,tb1.a5 from tb1 where not exists(select 1 from tb2 where isnull(tb2.a1,'') = isnull(tb1.a1,'') and isnull(tb2.a2,'') = isnull(tb1.a2,'') and isnull(tb2.a3,'') = isnull(tb1.a3,''))
update tb2
set a4 = tb1.a4, a5 = tb1.a5
from tb2 , tb1
where tb2.a1 = tb1.a1 and tb2.a2 = tb1.a2 and tb2.a3 = tb1.a32.
insert into tb2 select * from tb1 where not exists(select 1 from tb1 where tb2.a1 = tb1.a1 and tb2.a2 = tb1.a2 and tb2.a3 = tb1.a3)
解决方法:考虑效率问题。批量修改,添加。尽量少的做表链接和遍历。
方案(供参考):
1.将两表重复主键的数据备份到临时表里。
2.将临时表的数据更新到table2的a4,a5字段。
3.将table1 插入到table2 条件是table1的主键不在临时表里。
是不是和这个有关系呢,a3是我新增加的列又把它做为其中的一个联合主键之一,默认值设为了'0'
是不是和这个有关系呢,a3是我新增加的列又把它做为其中的一个联合主键之一,默认值设为了'0'