我想通過MS-SQL和MySql數據庫進行連接。如何在查詢中加入MS-SQL和MySQL表?
MS-SQL查詢有效地生成了一個索引,然後我想拉回所有與此查詢結果匹配的MySQL記錄。 (我可以帶回兩個表,即MySQL的未過濾數據,然後使用Linq進行過濾,但這樣會效率低下,因爲我將拉回比我需要更多的數據。)
MS-SQL查詢是通過LINQ的完成:
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 };
這將帶給我們一個表是這樣的:
RequestID | score
-----------------
12345 | 1
12349 | 3
12446 | 3
等
從這個我想從下面的MySQL只返回記錄查詢在上表中有一個請求ID:
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
即我只是想拉回來的記錄12345,在這個例子中12349和12446。最終,我想要一個單一表,其中包含requestID,分數以及MySQL查詢中的列。但是,如果我能夠獲得「已過濾」的MySQL表格,我可以在之後加入這兩個表格。我只是不想將MySQL重新帶回「未過濾」,因爲表格會很大。