SQL Select 数据 JOIN 过滤重复

Question

我在数据库中有记录:

Table Table 评估的替代 JOIN

SELECT a.id_alternative,a.value,a.id_criteria,b.name FROM saw_evaluations AS a JOIN saw_alternatives AS b ON a.id_alternative = b.id_alternative ORDER BY a.id_criteria ASC

id_alternative|value|id_criterias|name
-----------------------------------------
3|16|1|Mutiya
2|14|1|Restiyanti
2|3|2|Restiyanti
3|3|2|Mutiya
2|2|3|Restiyanti
3|3|3|Mutiya

尝试像这样使用 GROUP :

SELECT a.id_alternative, a.value, a.id_criteria, b.name FROM saw_evaluations AS a JOIN saw_alternatives AS b ON a.id_alternative = b.id_alternative GROUP BY a.id_criteria ORDER BY a.id_criteria ASC

id_alternative|value|id_criterias|name
-----------------------------------------
3|16|1|Mutiya
3|3|2|Mutiya
3|3|3|Mutiya

问题，我要结果数据记录：

id_alternative|value|id_criterias|name
-----------------------------------------
3|16|1|Mutiya
3|3|2|Mutiya
3|3|3|Mutiya
2|14|1|Restiyanti
2|3|2|Restiyanti
2|2|3|Restiyanti

请帮忙sql查询上面数据的结果？

Answer 1

你不需要 group by ，只需要 order by col1, col2

SELECT a.id_alternative, a.value, a.id_criteria, b.name 
FROM saw_evaluations AS a 
JOIN saw_alternatives AS b ON a.id_alternative = b.id_alternative 
ORDER BY b.id_alternative desc, a.id_criteria asc

Answer 2

尝试不使用 Group By 和 Order

SELECT a.id_alternative, a.value, a.id_criteria, b.name 
FROM saw_evaluations AS a JOIN saw_alternatives AS b ON a.id_alternative = b.id_alternative  
ORDER BY a.id_criteria DESC, value DESC

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