MYSQL子查询例题以及答案

More Subqueries Quizzes

Above is the ERD for the database again - it might come in handy as you tackle the quizzes below. You should write your solution as a subquery or subqueries, not by finding one solution and copying the output. The importance of this is that it allows your query to be dynamic in answering the question - even if the data changes, you still arrive at the right answer.

1. 1. 1. Provide the name of the sales_rep in each region with the largest amount of total_amt_usd sales.

         SELECT * FROM
         (SELECT rname rname,MAX(totalsum) totalsum
         FROM
         (SELECT r.name rname,s.name sname,SUM(total_amt_usd) totalsum
         FROM accounts a 
         JOIN orders o
         ON o.account_id = a.id
         JOIN sales_reps s
         ON a.sales_rep_id = s.id
         JOIN region r
         ON r.id = s.region_id
         GROUP BY r.name,s.name
         ORDER BY 1,3 desc ) sub
         GROUP BY rname ) t1
         JOIN
         (SELECT r.name rname,s.name sname,SUM(total_amt_usd) totalsum
         FROM accounts a 
         JOIN orders o
         ON o.account_id = a.id
         JOIN sales_reps s
         ON a.sales_rep_id = s.id
         JOIN region r
         ON r.id = s.region_id
         GROUP BY r.name,s.name
         ORDER BY 1,3 desc ) t2
         ON t1.rname = t2.rname
         WHERE t1.totalsum = t2.totalsum
         
         METHOD2

         WITH t1 AS (SELECT rname rname,MAX(totalsum) totalsum
         FROM
         (SELECT r.name rname,s.name sname,SUM(total_amt_usd) totalsum
         FROM accounts a
         JOIN orders o
         ON o.account_id = a.id
         JOIN sales_reps s
         ON a.sales_rep_id = s.id
         JOIN region r
         ON r.id = s.region_id
         GROUP BY r.name,s.name
         ORDER BY 1,3 desc ) sub
         GROUP BY rname ),

         t2 AS (SELECT r.name rname,s.name sname,SUM(total_amt_usd) totalsum
         FROM accounts a
         JOIN orders o
         ON o.account_id = a.id
         JOIN sales_reps s
         ON a.sales_rep_id = s.id
         JOIN region r
         ON r.id = s.region_id
         GROUP BY r.name,s.name
         ORDER BY 1,3 desc )

         SELECT *
         FROM t1
         JOIN t2
         ON t1.rname = t2.rname
         WHERE t1.totalsum = t2.totalsum

          

   2. For the region with the largest (sum) of sales total_amt_usd, how many total (count) orders were placed? 
      
      

   3. For the name of the account that purchased the most (in total over their lifetime as a customer) standard_qty paper, how many accounts still had more in total purchases? 
      
      

   4. For the customer that spent the most (in total over their lifetime as a customer) total_amt_usd, how many web_events did they have for each channel?
      
      

   5. What is the lifetime average amount spent in terms of total_amt_usd for the top 10 total spending accounts?
      
      

   6. What is the lifetime average amount spent in terms of total_amt_usd for only the companies that spent more than the average of all orders.

转载于:https://www.cnblogs.com/kouryoushine/p/9313667.html