Question

我有一个具有以下结构的CTE

ITEM,   DATE,       QUANTITY,   EXTRA
AAAA    01-07-2015  100         20
AAAA    04-07-2015  100         13
AAAA    07-07-2015  100         16
AAAA    09-07-2015  100         23
.
.
.
AAAA    31-07-2015  100         30

基本上，我想要做的是将记录中的“缺失日期”和前一记录中包含EXTRA的EXTRA字段（如下所示）取出

ITEM,   DATE,       QUANTITY,   EXTRA
AAAA    01-07-2015  100         20
AAAA    02-07-2015  0           20
AAAA    03-07-2015  0           20
AAAA    04-07-2015  100         13
AAAA    05-07-2015  0           13
AAAA    06-07-2015  0           13
AAAA    07-07-2015  100         16
AAAA    08-07-2015  0           16
AAAA    09-07-2015  100         23
.
.
.
AAAA    31-07-2015  100         30

我可以使用LAG和临时表的混合手动插入记录，其中包含完整的有效日期列表+ MERGE。但是，此CTE仅用于一次性检查然后处理。还有更好的方法吗？

Answer 1

请考虑以下事项：

我制作了代表您数据的CTE（不考虑ITEM，因为它与示例无关。）

使用以下两个CTE我正在使用data搜索可用recursive query的最小值和最大值之间的缺失日期。

接下来，您需要将data加入可用的dates。关键是从date获取最大data行，只要data.date不等于dates.date。

最后，我基于该示例的解释是，您希望继承extra，而不是quantity。因此case中的select - 语句。

with data as (
    select cast('2015-07-01' as date) date, 100 quantity, 20 extra union all
    select cast('2015-07-04' as date) date, 100 quantity, 13 extra union all
    select cast('2015-07-07' as date) date, 100 quantity, 16 extra union all
    select cast('2015-07-09' as date) date, 100 quantity, 23 extra
)

, maxDate as (
    select MAX(date) date
    from data
)

, dates as (
    select date
    from data

    union all

    select DATEADD(day,1,date) date
    from dates
    where DATEADD(day,1,date) not in (select date from data)
        and DATEADD(day,1,date) < (select date from maxDate)
)

select dates.date
, case dates.date when data.date then data.quantity else 0 end quantity
, data.extra
from dates
join data on data.date = (select max(date) from data where data.date <= dates.date)
order by 1

Answer 2

试试这个;

;with tbl as (
    --your data....
),
max_min_val as (
  select max(date) as max_date, min(date) as min_date from tbl
),
all_date AS (
    SELECT min_date as DateColumn 
    from max_min_val
    UNION ALL
    SELECT DATEADD(day,1,DateColumn)
    FROM all_date, max_min_val
    WHERE DATEADD(day,1,DateColumn) <= max_date
)
select 
    coalesce(t.item, (select top 1 tt.item from tbl tt where tt.date < x.DateColumn order by tt.date desc)) as item,
    x.DateColumn as date, 
    coalesce(t.QUANTITY, 0) as QUANTITY,
    coalesce(t.EXTRA, (select top 1 tt.EXTRA from tbl tt where tt.date < x.DateColumn order by tt.date desc)) as EXTRA
from all_date x
left join
tbl t on t.date = x.DateColumn

此处all_date将date之间的所有min and max date in tbl。
左连接all_date将提供所有日期

coalesce(t.QUANTITY, 0) as QUANTITY

t.QUANTITY

not null将0
EXTRA和item会根据CTE tbl从date提供以前的行数据。

在日期为关键字的CTE中插入“缺失记录”

2 个答案: