T-SQL 多重分组 [英] T-SQL Multiple grouping

问题描述

我有以下数据:

Product Price   StartDate                   EndDate
Apples  4.9     2010-03-01 00:00:00.000     2010-03-01 00:00:00.000
Apples  4.9     2010-03-02 00:00:00.000     2010-03-02 00:00:00.000
Apples  2.5     2010-03-03 00:00:00.000     2010-03-03 00:00:00.000
Apples  4.9     2010-03-05 00:00:00.000     2010-03-05 00:00:00.000
Apples  4.9     2010-03-06 00:00:00.000     2010-03-06 00:00:00.000
Apples  4.9     2010-03-09 00:00:00.000     2010-03-09 00:00:00.000
Apples  2.5     2010-03-10 00:00:00.000     2010-03-10 00:00:00.000
Apples  4.9     2010-03-11 00:00:00.000     2010-03-11 00:00:00.000
Apples  4.9     2010-03-12 00:00:00.000     2010-03-12 00:00:00.000
Apples  4.9     2010-03-13 00:00:00.000     2010-03-13 00:00:00.000
Apples  4.9     2010-03-15 00:00:00.000     2010-03-15 00:00:00.000
Apples  4.9     2010-03-16 00:00:00.000     2010-03-16 00:00:00.000

想要像 product, price, min(startdate), max(startdate) 这样进行分组，但也应该在开始日期和结束日期中进行分组............如下所示

want to group like product, price, min(startdate), max(startdate) but should have grouping in start date and end date as well........ something like below

想要的结果

Apples  4.9     2010-03-01 00:00:00.000     2010-03-02 00:00:00.000
Apples  2.5     2010-03-03 00:00:00.000     2010-03-03 00:00:00.000
Apples  4.9     2010-03-05 00:00:00.000     2010-03-09 00:00:00.000
Apples  2.5     2010-03-10 00:00:00.000     2010-03-10 00:00:00.000
Apples  4.9     2010-03-11 00:00:00.000     2010-03-16 00:00:00.000

推荐答案

我的方法.

数据:

create table t ( producte varchar(50), 
                 price money, 
                 start_date date,
                 end_date date);

insert into t values
( 'apple', 4.9, '2012-01-01', '2012-01-01' ),
( 'apple', 4.9, '2012-01-02', '2012-01-02' ),
( 'apple', 8, '2012-01-04', '2012-01-04' ),
( 'cat', 5, '2012-01-01', '2012-01-01' ),
( 'cat', 6, '2012-01-02', '2012-01-02' ),
( 'cat', 6, '2012-01-03', '2012-01-03' );

查询:

with start_dates as (
  select 
    t.producte, t.price, t.start_date, t.end_date, t.start_date as gr_date    
  from 
    t left outer join 
    t t1 on 
        t.price = t1.price and                         --new
        t.producte = t1.producte and
        t.start_date = dateadd(day,1, t1.end_date )
  where t1.producte is null
  union all
  select 
      t.producte, t.price, t.start_date,t. end_date, gr_date
  from
      t inner join 
      start_dates t1 on  
        t.price = t1.price and                         --new
        t.producte = t1.producte and
        t.start_date = dateadd(day,1, t1.end_date )
)
select t.producte, t.price , min( t.start_date ), max( t.end_date )
from start_dates t
group by  t.producte, gr_date  ,t.price

结果:

| PRODUCTE | PRICE |   COLUMN_2 |   COLUMN_3 |
----------------------------------------------
|    apple |   4.9 | 2012-01-01 | 2012-01-02 |
|    apple |     8 | 2012-01-04 | 2012-01-04 |
|      cat |     5 | 2012-01-01 | 2012-01-01 |
|      cat |     6 | 2012-01-02 | 2012-01-03 |

说明

这是一个递归 CTE 表达式.基本查询获取每组价格的初始日期.递归查询查找具有此价格的最后一条数据.

This is a recursive CTE expression. Base query take inital dates for each group of prices. Recursive query looks for last data with this price.

这篇关于T-SQL 多重分组的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！