Real MySQL interview question (30) -- shell real estate order analysis

Real estate order analysis

“ Transaction order form ” It records a real estate platform （ It's like chain home 、 Shells, etc ） Details of daily house transactions .（ Shell interview questions ）

Field “ Transaction source channel ” The value in is “ Source character ”、“ The owner entrusts online ”、“null” Indicates offline channels , The rest of the transaction source channels are online .
requirement ：
1． As of yesterday, the volume of second-hand online transaction orders accounted for （ Including parking space ）>=50% Your store can win awards ;
（ Proportion of online transactions = Online order volume / Total number of orders ）
2． The number of stores that meet the award-winning conditions 1 If you trade on a single line, you can get 200 garena （ Can be used to exchange for bonuses ）, The first 2 Single can get 400 garena , The first 3 Single and above can obtain 800 garena , But the garage doesn't reward （ Field “ The purpose of the house is ” The value in is ” Parking lot ”、” The garage ” Think it's a garage ）;
3. In a continuous SQL Realize the above requirements in , Cannot be split into multiple SQL, The table fields that must be output are as follows （ Can increase the ）;

WITH t1 AS(--  Find out whether it is online 
SELECT *,
CASE WHEN  Transaction source channel  IN(' Source character ',' The owner entrusts online ') OR  Transaction source channel  IS NULL THEN ' no ' ELSE ' yes ' END AS  Online or not 
FROM  Transaction order form 
),
t2 AS (--  Calculate the online transaction proportion of each store 
SELECT  Contracted broker stores ,SUM(CASE WHEN  Online or not =' yes ' THEN 1 ELSE 0 END)/COUNT(*) AS  The proportion of online transactions in the store where the broker is located 
FROM t1
GROUP BY  Contracted broker stores 
),
t3 AS (--  Get the original table plus the previous request 2 A field , And add an online order sort 
SELECT t1.*,t2. The proportion of online transactions in the store where the broker is located ,
row_number()over(PARTITION BY  Contracted broker stores  ORDER BY  Signing time ) AS  Order sequence 
FROM t1
JOIN t2
ON t1. Contracted broker stores =t2. Contracted broker stores 
WHERE  Online or not =' yes '
AND  The proportion of online transactions in the store where the broker is located >=0.5
AND  The purpose of the house is  IS NULL
),
t4 AS (--  Match all the orders for shell coins 
SELECT *,
CASE WHEN  Order sequence =1 THEN '200'
WHEN  Order sequence =2 THEN '400'
WHEN  Order sequence >=3 THEN '800'
ELSE 0 END AS  Shell currency shall be issued for this order 
FROM t3
)
SELECT t1.*,t2. The proportion of online transactions in the store where the broker is located ,IFNULL(t4. Shell currency shall be issued for this order ,0) AS  Shell currency shall be issued for this order 
FROM t1
LEFT JOIN t2
ON t1. Contracted broker stores =t2. Contracted broker stores 
LEFT JOIN t4
ON t1. agreement id=t4. agreement id
ORDER BY  Contracted broker stores , Signing time 

give the result as follows ：