[英]How can I join a MS-SQL and MySQL table in a query?
I want to do a join accross a MS-SQL and MySql database. 我想在MS-SQL和MySql数据库中进行连接。
The MS-SQL query generates an index, effectively, and then I want to pull all MySQL records back that match the result of this query. MS-SQL查询有效地生成一个索引,然后我想拉回所有匹配此查询结果的MySQL记录。 (I could bring back both tables, ie the unfiltered data from MySQL and then filter using Linq, but this will be inefficient as I'll be pulling back loads more data than I need.)
(我可以带回两个表,即来自MySQL的未过滤数据,然后使用Linq过滤,但这将是低效的,因为我将撤回加载的数据超出我的需要。)
The MS-SQL query is done via Linq: MS-SQL查询是通过Linq完成的:
var fb1 = from f in db.tl_feedbacks
where f.timestamp >= new DateTime(fromYear, fromMonth, fromDay)
&& f.timestamp <= new DateTime(toYear, toMonth, toDay)
select new {f.requestID, f.tl_feedback_score.score };
This will bring back a table like this: 这将带回一个这样的表:
RequestID | score
-----------------
12345 | 1
12349 | 3
12446 | 3
etc. 等等
From this I want to return only those records from the following MySQL query that have a RequestID in the above table: 从这里我想只返回以下MySQL查询中具有上表中的RequestID的记录:
SELECT wo.WORKORDERID,
COALESCE(ti.FIRST_NAME,'Not Assigned') AS 'Technician',
COALESCE(cd.CATEGORYNAME, 'Not Assigned') AS Category,
COALESCE(scd.NAME, 'Not Assigned') AS Subcategory,
wof.UDF_CHAR1 "Office Location"
FROM WorkOrder_Threaded wot
INNER JOIN WorkOrder wo ON wot.WORKORDERID=wo.WORKORDERID
LEFT JOIN SDUser sdu ON wo.REQUESTERID=sdu.USERID
LEFT JOIN AaaUser aau ON sdu.USERID=aau.USER_ID
LEFT JOIN WorkOrderStates wos ON wo.WORKORDERID=wos.WORKORDERID
LEFT JOIN SDUser td ON wos.OWNERID=td.USERID
LEFT JOIN AaaUser ti ON td.USERID=ti.USER_ID
LEFT JOIN CategoryDefinition cd ON wos.CATEGORYID=cd.CATEGORYID
LEFT JOIN SubCategoryDefinition scd ON wos.SUBCATEGORYID=scd.SUBCATEGORYID
LEFT JOIN WorkOrder_Fields wof ON wo.WORKORDERID=wof.WORKORDERID
ie I only want to pull back records 12345, 12349 and 12446 in this example. 即我只想在这个例子中撤回记录12345,12349和12446。 Ultimately I want one single table which has the requestID, score, and the columns from the MySQL query.
最终我想要一个具有requestID,得分和MySQL查询列的单个表。 However, if I can get the "filtered" MySQL table back I can join the two afterwards.
但是,如果我可以获得“过滤”的MySQL表格,我可以加入这两个表格。 I just don't want to bring the MySQL back "unfiltered" as the table will be huge.
我只是不想把MySQL带回“未经过滤”,因为这个表会很大。
With the right OLEDB database drivers (I've only done this with PGSQL so I can't really advise), you can create a Linked Server in MSSQL. 使用正确的OLEDB数据库驱动程序(我只使用PGSQL完成此操作,因此我无法提供建议),您可以在MSSQL中创建链接服务器 。 Here's a walkthrough , and here's another .
这是一个演练 , 这是另一个 。
You can then query it using OPENQUERY as follows in MSSQL: 然后,您可以使用OPENQUERY在MSSQL中按如下方式查询它:
select * from openquery(LinkedServerDb,'select * from remotetable')
and join: 并加入:
select
*
from
openquery(LinkedServerDb,'select * from remotetable') remoteTable
join localTable on remotetable.someid=localtable.otherid
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