Question

表ProductOrder列包括：

id   shopid starttime endtime 
1    123    2018-04-27  2018-04-28
2    234    2018-04-23  2018-04-30
3    189    2018-05-01  2018-05-30
4    321    2018-05-01  2018-05-29

我不想查询两天之间的有效店铺数量并按最近一个月的每一天计算，有效的店铺数量表示开始时间＆lt; = $ curDate＆lt; = endtime，而curDate是每天的变量最糟糕的一个月。

今天是2018-04-27，所以查询结果应为：

day          count
2018-04-27    2
2018-04-26    1
2018-04-25    1
2018-04-24    1
2018-04-23    1
2018-04-22    0
2018-04-21    0
……………………………………
2018-03-26    0

我在MYSQL中实现了这个要求。这个SQL在MYSQL中可以很好地工作。如何转换为Hive Sql？

SELECT
    DATE_SUB(DATE(NOW()), INTERVAL days_ago.days DAY) day,
    COUNT(distinct(shopID)) count
FROM
(SELECT 0 days UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION
 SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9 UNION
 SELECT 10 UNION SELECT 11 UNION SELECT 12 UNION SELECT 13 UNION SELECT 14 UNION
 SELECT 15 UNION SELECT 16 UNION SELECT 17 UNION SELECT 18 UNION SELECT 19 UNION
 SELECT 20 UNION SELECT 21 UNION SELECT 22 UNION SELECT 23 UNION SELECT 24 UNION
 SELECT 25 UNION SELECT 26 UNION SELECT 27 UNION SELECT 28 UNION SELECT 29)
    AS days_ago
LEFT JOIN ProductOrder
    ON DATE_SUB(DATE(NOW()), INTERVAL days_ago.days DAY) <= ProductOrder.endtime
    AND DATE_SUB(DATE(NOW()), INTERVAL days_ago.days DAY) >= ProductOrder.starttime
    AND status = 2
GROUP BY days_ago.days;

Answer 1

Hive不支持非等连接条件，它们可以放在WHERE子句中。使用STACK代替许多UNION子查询。

select DATE_SUB(CURRENT_DATE, days_ago.days) day, 
       COUNT(DISTINCT(shopID)) count 
from
(
select stack(30, --the number of elements
           0,  1,  2,  3,  4,  5,  6,  7,  8,  9,
          10, 11, 12, 13, 14, 15, 16, 17, 18, 19,
          20, 21, 22, 23, 24, 25, 26, 27, 28, 29) as (days) 
 ) days_ago
LEFT JOIN ProductOrder po ON status = 2
WHERE (DATE_SUB(CURRENT_DATE, days_ago.days) <= po.endtime  
  AND DATE_SUB(CURRENT_DATE, days_ago.days) >= po.starttime)
   OR po.shopID is NULL --allow nulls  
GROUP BY DATE_SUB(CURRENT_DATE, days_ago.days);

Answer 2

SELECT DATE_SUB(CURRENT_DATE, days_ago.days), 
       COUNT(DISTINCT(shopID)) count 
FROM
(
    SELECT explode(array(
           0,  1,  2,  3,  4,  5,  6,  7,  8,  9,
          10, 11, 12, 13, 14, 15, 16, 17, 18, 19,
          20, 21, 22, 23, 24, 25, 26, 27, 28, 29)) as days
) days_ago 
LEFT JOIN ProductOrder po ON 
(
    DATE_SUB(CURRENT_DATE, days_ago.days) <= po.endtime  
    AND DATE_SUB(CURRENT_DATE, days_ago.days) >= po.starttime 
    AND status = 2
) 
GROUP BY days_ago.days;

如何将这个MYSQL SQL转换为HIVE SQL？

2 个答案: