MySQL如何返回唯一/不同的结果? [英] MySQL How to Return Unique/Distinct Results?

问题描述

我正在运行以下MySQL查询，以查找没有手册(且车轮有黑轮等)的汽车

I'm running the following MySQL query to find cars that don't have manuals (and have black wheels, etc.)

SELECT `cars`.* FROM `cars`
INNER JOIN wheels ON cars.id = wheels.car_id
LEFT OUTER JOIN manuals ON cars.id = manuals.car_id
WHERE (cars.created_at > '2010-09-09'
AND wheels.color = 'Black'
AND wheels.created_at < '2011-01-05'
AND manuals.car_id IS NULL)

查询的结果看起来正确，但是它两次返回ID为27的汽车.如何更改查询，使所有结果都是唯一的(无重复)?

The results of the query look correct, but it returns the car with id 27 twice. How do I change the query so that all results are unique (no duplicates)?

推荐答案

您可以尝试使用 SELECT DISTINCT 代替 SELECT

You could try SELECT DISTINCT instead of SELECT

这篇关于MySQL如何返回唯一/不同的结果?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！