Question

我有下表。我想通过在日期上添加条件来对行中存在的值求和。

Table - a
  ID   Entry_date     weight  height   ID1      start_date  end_date
 111   2001-03-31      43      187
 111   2001-04-30      23      165
 111   2001-05-31      34      172     111      2001-04-30  2001-05-31 
 112   2001-06-30      54      183
 112   2001-07-31      26      188     112      2001-06-30  2001-07-31
 113   2001-04-30      23      165
 113   2001-05-31      34      172     113      2001-04-30  2001-05-31 
 114   2001-05-31      46      177
 114   2001-06-30      54      183
 114   2001-07-31      26      188     114      2001-06-30  2001-07-31

如果Entry_date >= start_date and Entry_date <= end_date那么它应该对那些entry_dates和ID的权重和高度求和。我不知道我是否正确解释了。结果表应该是这样的：

Table - 

      ID   Entry_date     weight  height   ID1      start_date  end_date
     111   2001-03-31      43      187    
     111   2001-05-31      57      337     111      2001-04-30  2001-05-31 
     112   2001-07-31      80      371     112      2001-06-30  2001-07-31 
     113   2001-05-31      57      337     113      2001-04-30  2001-05-31 
     114   2001-05-31      46      177
     114   2001-07-31      80      371     114      2001-06-30  2001-07-31

我试过以下：

Select ID, Entry_date, sum(weight) as weight, sum(height) as height, ID1, start_date, end_date from table a 
where Entry_date >= start_date and Entry_date <= end_date group by ID, Entry_date;

但它没有给我想要的结果。它给了我以下结果：

  Table - a
          ID   Entry_date     weight  height   ID1      start_date  end_date
         111   2001-05-31      34      172     111      2001-04-30  2001-05-31 
         112   2001-07-31      26      188     112      2001-06-30  2001-07-31
         113   2001-05-31      34      172     113      2001-04-30  2001-05-31 
         114   2001-07-31      26      188     114      2001-06-30  2001-07-31

有谁能告诉我如何处理这个案子？

Answer 1

这有点复杂。这是您可以尝试的查询：

select
  id, entry_date,

  (select sum(weight) from test 
   where entry_date between a.start_date and a.end_date
   and id = a.id) as weight,

  (select sum(height) from test
   where entry_date between a.start_date and a.end_date
   and id = a.id) as height,

  id1, start_date, end_date
from test a
where start_date is not null and end_date is not null

union all

select a.* 
from test a
left join test b 
  on a.id = b.id
where 
  (a.start_date is null and a.end_date is null)
  and (b.start_date is not null and b.end_date is not null)
  and not a.entry_date between b.start_date and b.end_date

order by id, entry_date

UNION ALL子句上方的查询将提取对重量和高度进行数学运算的记录。 UNION ALL子句下面的查询仅关注不在所需范围内且具有空日期的记录。您可以轻松调整它。

示例：http://sqlfiddle.com/#!9/f9b54a/6

查询相同信息的备用方法

select e.id, 
    max(entry_date) as entry_date, sum(weight) as weight, sum(height) as height,
    em.start_date, em.end_date
from test e
inner join (
  select distinct id, start_date, end_date
  from test
  where start_date is not null and end_date is not null) em
  on em.id = e.id
  and e.entry_date between em.start_date and em.end_date
group by e.id, em.start_date, em.end_date

union all

select e.id, entry_date, weight, height, em.start_date, em.end_date
from test e
inner join (
  select distinct id, start_date, end_date
  from test
  where start_date is not null and end_date is not null) em
    on em.id = e.id
    and not e.entry_date between em.start_date and em.end_date

order by id, entry_date

示例：http://sqlfiddle.com/#!9/f9b54a/8

更好的数据存储方法

create table entrymaster (
  id int,
  start_date date,
  end_date date
);

create table entries (
  id int,
  entry_date date,
  weight int,
  height int
);

select e.id, 
    max(entry_date) as entry_date, sum(weight) as weight, sum(height) as height,
    em.start_date, em.end_date
from entries e
inner join entrymaster em
  on em.id = e.id
  and e.entry_date between em.start_date and em.end_date
group by e.id, em.start_date, em.end_date

union all

select e.id, entry_date, weight, height, em.start_date, em.end_date
from entries e
inner join entrymaster em
    on em.id = e.id
    and not e.entry_date between em.start_date and em.end_date

order by id, entry_date

示例：http://sqlfiddle.com/#!9/7eaaa/3

Answer 2

Select ID, Entry_date, sum(weight) as weight, sum(height) as height, ID1, start_date, end_date from table a 
where Entry_date >= start_date and Entry_date <= end_date group by ID, Entry_date, ID1;

将ID1添加到组中。

但是这个查询可能无法移植到某些数据库引擎，因为如果有多行（first，min，max等），你不会告诉服务器它应该从start_date和end_date得到什么值？）。

带有条件的MySQL中Row的值的总和

2 个答案: