从相同的 table 但不同的数据库中获取连接中的一列

Get One column in join from same table but different database

我有两个数据库。

一个。 DB_1 b. DB_2

比方说,我目前正在使用 DB_1 进行以下查询

Select top 1 a.mkey,convert(varchar(255), a.ref_date,103) as REF_DATE,  cd.type_desc as DOC_TYPE,  a.doc_no as INWARD_NO, 
                       cr.type_desc as dept_received, e.emp_name as EMP_RECEIVED,    
                       convert(varchar(255), a.doc_date,103) as date,   
                       a.to_user, a.No_of_pages, Ref_No,    
                       e.emp_name as NAME,    
                       coalesce(e.Email_Id_Official, 'test@test.com') EMAILID, a.Party_Name                           
                from inward_doc_tracking_hdr a left join   
                     type_mst_a cd   
                     on a.doc_type = cd.master_mkey left join  
                   type_mst_a cr   
                     on a.dept_received = cr.master_mkey 
                     and cr.type_code='D1'  
                     left join  emp_mst e  
                     on a.emp_received = e.mkey   
                     where a.emp_received is not null and
                        a.mkey = 146

现在我想要的是。我想从另一个数据库 (DB_2) 加入相同的 table 怎么办??

更新

我的另一个数据库列名称是 Inward_ref_key,它的 table 名称是 inward_doc_tracking_hdr

假设两个数据库都在同一台服务器上,您所要做的就是将另一个数据库指定为 table 标识符的一部分:

DB_2.dbo.inward_doc_tracking_hdr

如果您的 table 属于不同的架构(不是 dbo),请指定该架构名称。

为了从另一个数据库中引用 table,您可以这样做:

DB_2.<schema>.<table_name>

如果它们有不同的排序规则,请小心

SELECT local.name AS LocalLogins, linked.name AS LinkedLogins  
FROM master.sys.server_principals AS local  
LEFT JOIN [SRVR002\ACCTG].master.sys.server_principals AS linked  
ON local.name = linked.name ;  
GO  

这里的 [SRVR002\ACCTG] 是 DB 的名称,如果您已经创建了 DBlink,这应该有效

正如讨论的那样。请参阅下面的答案。

SELECT TOP 1 a.mkey,
    CONVERT(VARCHAR(255), a.ref_date,103) AS REF_DATE, 
    cd.type_desc AS DOC_TYPE, 
    a.doc_no AS INWARD_NO, 
    cr.type_desc AS dept_received, 
    e.emp_name AS EMP_RECEIVED, 
    CONVERT(VARCHAR(255), a.doc_date,103) AS DATE, 
    a.to_user,
    a.No_of_pages,
    Ref_No, 
    e.emp_name AS NAME, 
    COALESCE(e.Email_Id_Official, 'test@test.com') EMAILID, 
    a.Party_Name, 
    doc_no = (SELECT TOP 1 doc_no FROM erp190516.dbo.inward_doc_tracking_hdr WHERE mkey = a.inward_ref_key)
    OLD_DOC_NO 
FROM inward_doc_tracking_hdr a 
LEFT JOIN type_mst_a cd 
    ON cd.master_mkey  = a.doc_type  
LEFT JOIN type_mst_a cr 
    ON cr.master_mkey = a.dept_received 
    AND cr.type_code='D1' 
LEFT JOIN emp_mst e 
    ON  e.mkey = a.emp_received
WHERE a.emp_received IS NOT NULL 
AND a.mkey = 146