如何从sql数据库中按自定义id获取特定产品和组的最大计数

我有以下数据库，需要从SQL数据库中获取具有group by customer id的特定产品的最大计数

我尝试使用SQL子查询，但无法解决。请帮我解决这个问题

如果产品名称为

bajari

，我需要如下输出：

标准SQL使用

分组依据
子查询使用
聚合：

select customer_id, Product_name, count(*) mostcount
from table t
group by customer_id, Product_name
having count(*) = (select max(counts) 
                   from (select customer_id, count(*) counts
                         from table t
                         group by customer_id, Product_name)
                  );

标准SQL使用
groupby
clause和
subquery
聚合：

select customer_id, Product_name, count(*) mostcount
from table t
group by customer_id, Product_name
having count(*) = (select max(counts) 
                   from (select customer_id, count(*) counts
                         from table t
                         group by customer_id, Product_name)
                  );

使用以下查询

select customer_id, product_name, count(product_name) as mostcount from `products`  where product_name='bajari' group by customer_id having count(product_name) =
( select max(mostcount) as highest_total
    from (
         select customer_id
              , count(product_name) as mostcount
           from `products` where product_name='bajari'
         group
             by customer_id
         ) as t
);

对于分步解决方案，请检查相同的解决方案

希望这对你有帮助
 使用以下查询

select customer_id, product_name, count(product_name) as mostcount from `products`  where product_name='bajari' group by customer_id having count(product_name) =
( select max(mostcount) as highest_total
    from (
         select customer_id
              , count(product_name) as mostcount
           from `products` where product_name='bajari'
         group
             by customer_id
         ) as t
);

<% find_array_max = [] %>
<% count = 0%>
<%@customers.each do |customer|%>
  <%  count = @products.where(product_name: 'bajari', customer_id: customer.id).sum(:weight)%>
  <% find_array_max.push(count) %>
<% end -%>
  <%= find_array_max.max%>.kg
  <%= find_array_max.min%>.kg

对于分步解决方案，请检查相同的解决方案

希望这对你有帮助
 

<% find_array_max = [] %>
<% count = 0%>
<%@customers.each do |customer|%>
  <%  count = @products.where(product_name: 'bajari', customer_id: customer.id).sum(:weight)%>
  <% find_array_max.push(count) %>
<% end -%>
  <%= find_array_max.max%>.kg
  <%= find_array_max.min%>.kg

公斤
公斤

公斤
公斤
编辑你的问题并显示你想要的结果。是的，我已更新我的问题如果有联系怎么办？编辑你的问题并显示你想要的结果。是的，我已更新我的问题如果有联系怎么办？