Question

我有2个数据库，即db1，db2。我需要一个从这些dbs（db1，db2）获取数据的查询，每个dbs都有2个表（特许，发票）。

在db1.concessions =＆gt;中让步是主要关键。 db1.invoicing =＆gt; [特许号]是主键

同样在db2.concessions =＆gt;中让步是主要关键。 db2.invoicing =＆gt; [特许号]是主键

在database1

中

db1.tbl1 =＆gt;特许权表有数据

    concession
    TH-123
    TH-456
    FP-789
    NZ-609

db1.tbl2 =＆gt;发票表有数据

    [Concession Number]          invoiced_on
    TH-322                        10.09.10
    TH-900                        23.10.10
    FP-675                        04.05.09
    NZ-111                        19.11.08

幸运的是，在数据库中，特许权的价值是独一无二的。特许权。[特许权] =开具发票。[特许经营号码]不产生数据..

在database2中：

db1.tbl1 =＆gt;特许权表有数据

    concession
    TH-123
    FP-789
    NZ-999
    TH-900

db1.tbl2 =＆gt;发票表有数据

    [Concession Number]          invoiced_on(dd.mm.yy)
    TH-456                        18.01.06
    TH-777                        23.10.04
    FP-675                        03.05.09
    NZ-149                        26.11.08

在db2让步中是独特的，让步。[特许] =开具发票。[特许号]没有数据..

现在查询应该获取具有公共记录的记录 db1。（concessions.concession OR invoicing.concession number）= db2（concessions.concession OR invoicing.concession number）

在样本数据中应返回TH-123，FP-789，NZ-999，FP-675。

我的第二个问题是有可能将此查询扩展到多个数据库。我无法将数据库的数量更改为1，因为它们已经已修复。请让我知道相同的最佳程序。

我试过这样的事情，有语法错误，

SELECT a.concession as db1_CON_NUMBER FROM db1.dbo.concessions as a  UNION 
SELECT b.[Concession Number] as db1_CON_NUMBER  FROM db1.dbo.invoicing as b 
INNER JOIN 
SELECT c.concession as db2_CON_NUMBER FROM db2.dbo.concessions as c  UNION 
SELECT d.[Concession Number] as db2_CON_NUMBER  FROM db2.dbo.invoicing as d 
ON db1_CON_NUMBER = db2_CON_NUMBER

希望你能回答这两个问题。感谢您耐心阅读这么长的邮件！

Answer 1

如果用户具有权限，您可以直接引用其他数据库。

<database>.<user>.<tablename>

是数据库表的完整“路径”。

经常使用

db1.dbo.tbl1 join db2.dbo.tbl2

其中dbo是数据库所有者的默认值，默认情况下，任何不属于特定用户的表都由dbo拥有。

UPDATE

要使查询验证，您可以将其扩展为此

SELECT * FROM 
(SELECT a.concession as db1_CON_NUMBER FROM db1.dbo.concessions as a  
UNION 
SELECT b.[Concession Number] as db1_CON_NUMBER FROM db1.dbo.invoicing as b ) c

INNER JOIN 

(SELECT c.concession as db2_CON_NUMBER FROM db2.dbo.concessions as a 
UNION 
SELECT b.[Concession Number] as db2_CON_NUMBER FROM db2.dbo.invoicing as b ) d

ON db1_CON_NUMBER = db2_CON_NUMBER

但我没有时间检查这是否会返回正确的数据，但您可以进行测试。

Answer 2

如果数据库位于同一SQL Server实例上，则可以使用3部分命名：

database_name.schema_name.object_name

Using Identifiers As Object Names

如果数据库不在同一个实例上，请创建链接服务器：Linked Servers

Creating Linked Servers (SQL Server Database Engine)

链接服务器允许访问分布式，异构查询针对OLE DB数据源。之后链接服务器已创建，分发可以针对此运行查询服务器和查询可以连接表来自多个数据源。如果链接服务器定义为 SQL Server的实例，远程存储程序可以执行。

Answer 3

select * from(
SELECT a.concession as db1_CON_NUMBER FROM BABMwork6_5_3108.dbo.concessions as a  
        WHERE (a.manuell_archive_delete! = 'Delete' OR  a.manuell_archive_delete IS NULL) 
UNION SELECT b.[Concession Number] as db1_CON_NUMBER  FROM BABMwork6_5_3108.dbo.invoicing as b) as tbl1 
INNER JOIN 
(SELECT c.concession as db2_CON_NUMBER FROM BABMwork6_6_2909.dbo.concessions as c  
        WHERE (c.manuell_archive_delete! = 'Delete' OR  c.manuell_archive_delete IS NULL) 
UNION SELECT d.[Concession Number] as db2_CON_NUMBER  FROM BABMwork6_6_2909.dbo.invoicing as d ) as tbl2
ON tbl1.[db1_CON_NUMBER] = tbl2.[db2_CON_NUMBER]

跨多个数据库连接查询 - 语法错误

3 个答案: