2017-09-25 32 views
-6

一個記錄我有這個疑問,它連接兩個表,並給我所有的數據結果一個一個條件CATID獲得基於catname

「錄像」

SELECT 
pm_categories_images.Image, 
pm_categories_images.FileURL, 
pm_categories.catname, 
pm_categories.`status`, 
pm_categories.sortorder, 
pm_categories.parentID, 
pm_categories_images.CatID 
FROM 
pm_categories 
LEFT JOIN pm_categories_images ON pm_categories_images.CatID = pm_categories.catID 
where pm_categories_images.CatID IN (select catid from pm_categories where 
parentID = (select catID from pm_categories where catname = 'Videography')) 

現在這部錄像帶有這樣的結果

http://prntscr.com/gpkuyl

現在我想1記錄每catname

+0

任何特定的 「記錄」 或只是 「紀錄」? (就像最近的那個,parentID最高的那個,排序次序最低的那個?什麼?mySQL擴展了這個組,所以你可以用catName來分組,但我不認爲這真的是你想要的第一個 – xQbert

+0

第一個其中一個就足夠了 – reev

+0

數據庫表沒有順序;你必須設置一個,所以你首先指的是排序順序最低的順序?另外where where子句將左連接否定爲只有圖像pm_Category將被顯示最後,什麼是PM_Categories的主鍵? – xQbert

回答

0

沒有一個MCVE和實際需求上的圖像從圖像表和更好的理解想爲什麼你需要一個左您的where子句使得當加入它表現得像一個內在......以及爲什麼where子句如此複雜......我真的不確定問題出在什麼後面......這是一個鏡頭......和一個DEMO:http://rextester.com/CRBN50943

樣本數據的預期結果總是好的:我做了我自己的和幾個假設

我把這個問題描述爲:我想要一個類別列表,以及每個類別具有最早字母值的圖像。

SELECT 
CI.Image, 
CI.FileURL, 
C.catname, 
C.`status`, 
C.sortorder, 
C.parentID, 
CI.CatID 
FROM pm_categories C 
INNER JOIN pm_categories_images CI 
    ON CI.CatID = C.catID 
INNER JOIN (SELECT Min(Image) MI, catID FROM pm_categories_images group by CATID) Z 
on CI.Image = Z.MI 
and CI.CatID = Z.CatId 
##WHERE C.catname = 'Videography' 
Order by sortOrder 

給予我們

+----+------------+-----------------------------------------------+-------------+--------+-----------+----------+-------+ 
| | Image |     FileURL     | catname | status | sortorder | parentID | CatID | 
+----+------------+-----------------------------------------------+-------------+--------+-----------+----------+-------+ 
| 1 | guid1.jpg | https://drive.google.com/BusinessID/Postings/ | Real Estate |  1 |   1 | NULL  |  1 | 
| 2 | guid4.jpg | https://drive.google.com/BusinessID/Postings/ | commercial |  1 |   2 | NULL  |  2 | 
| 3 | guid6.jpg | https://drive.google.com/BusinessID/Postings/ | Videography |  1 |   3 | NULL  |  3 | 
| 4 | guid10.jpg | https://drive.google.com/BusinessID/Postings/ | Other  |  1 |   4 | NULL  |  4 | 
| 5 | guid11.jpg | https://drive.google.com/BusinessID/Postings/ | LackingMCVE |  1 |   5 | NULL  |  5 | 
+----+------------+-----------------------------------------------+-------------+--------+-----------+----------+-------+