Question

如何让DISTINCT函数只查看一列？

SELECT DISTINCT
    id AS uniqueid,
    ProductCode AS ProductID,
    DisplayName AS ReportingLabel,
    REPLACE(URL, 'http', 'https') AS URL,
    ProductCategory AS Category,
    Description,
    CONCAT('https://', ImageURL) AS Image,
    latestSellingPrice AS Price,
    Brand,
    IF(latestSellingPrice > 300,
        'TRUE',
        'FALSE') AS Is_Default,
    IF(StockAvailable > 0, 'TRUE', 'FALSE') AS InStock
FROM
    XML_Import_Server
WHERE
    Brand = 'Totalsports' 
AND 
    DisplayName <> 'eGift Card'

由于尺寸和颜色选项，ProductCode并不总是唯一的。但我只需要拉出它的第一个变体。

Answer 1

你可以使用聚合功能和分组例如，对于某些列

SELECT DISTINCT
  id AS uniqueid,
  min(ProductCode) AS ProductID,
  DisplayName AS ReportingLabel

FROM
    XML_Import_Server
WHERE
    Brand = 'Totalsports' 
AND 
    DisplayName <> 'eGift Card'    
group by id, DisplayName

Answer 2

第一个变种并不清楚你的意思。所以我猜你的意思是具有最低import { Col, Navbar, Nav, NavItem } from 'react-bootstrap'值的变体。

使用加入主表的子查询执行此操作。子查询查找相关的id值。

id

尝试这样说服自己，它为每个不同的SELECT MIN(id) id FROM XML_Import_Server GROUP BY ProductCode值提供了正确的选择。

然后，将其加入主查询。

ProductCode

MySQL DISTINCT由一列组成

2 个答案: