如何在sql中使用distinct [英] how to use distinct in sql

问题描述

表：

 image_id标题image_path 
  1 测试../UploadedImage/images （ 4 ）。jpg 
  2  rose ../UploadedImage/Hydrangeas.jpg 
  3 测试../UploadedImage/Desert.jpg 
  4  rose ../UploadedImage/下载（ 1 ）。jpg 

如何获得如下结果

 Title image_path 
 Test ../UploadedImage/images（ 4 ）。jpg 
 rose ../UploadedImage/ Hydrangeas.jpg 
 

我想选择不同的标题，但相同的标题有多个图像

选择前1条记录

任何人帮我吗？

解决方案

你不想要DISTINCT - 你想使用子查询：

< pre lang =sql> SELECT Image_id，Tit le，Image_path FROM
（ SELECT *，ROW_NUMBER（） OVER （ PARTITION BY 标题 ORDER 按 Image_Id） AS rn FROM MyTable）x
WHERE rn = 1

Table:

image_id	Title	image_path	
1	Test	../UploadedImage/images (4).jpg
2	rose	../UploadedImage/Hydrangeas.jpg	
3	Test	../UploadedImage/Desert.jpg	
4	rose	../UploadedImage/download (1).jpg	

How do i get Result like below

 Title      image_path
Test ../UploadedImage/images (4).jpg
 rose    ../UploadedImage/Hydrangeas.jpg

I wanna select distinct by Title ,But Same title have multilple Images
select Top 1 Records
any body help me?

解决方案

You don't want DISTINCT - you want to use a subquery:

SELECT Image_id, Title, Image_path FROM
       (SELECT  *, ROW_NUMBER() OVER (PARTITION BY Title ORDER By Image_Id ) AS rn FROM MyTable) x
WHERE rn = 1

这篇关于如何在sql中使用distinct的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！