[英]MYSQL SELECT To fetch rows from two tables with or without a foreign key
[英]how to select distinct rows from two tables linked with foreign key
我想顯示數據庫中的圖像。我有兩個表gallery_photos
我想顯示任何帶有category_name的photos_filename。 photo_category是category_id的外鍵
我寫的mysql查詢
SELECT distinct a.category_name
,b.photo_filename
FROM gallery_category a
inner join gallery_photos b on (a.category_id=b.photo_category)
請幫助我做到這一點...
我想選擇完全像這樣
albums/1456226111.jpg interior
albums/1456226239.jpg graphics
albums/1456226339.jpg random
albums/1456226478.jpg goods
您可以按分組方式進行分組
SELECT a.category_name,b.photo_filename
FROM gallery_category a JOIN gallery_photos b
ON a.category_id=b.photo_category
GROUP BY a.category_name
使用“左聯接”將所有行保留在左表中。
SELECT
b.photo_filename,
a.category_name
FROM
gallery_category a LEFT join gallery_photos b ON (a.category_id=b.photo_category)
看一下這個!
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