Question

我有两列，年份和工资期（1,2,3,4 ......）。我正绞尽脑汁试图弄清楚如何根据这些来做一个介于两者之间。

例如说我有：

2017      1
2017      2
2017      3
2017      4
-------------v   
2017      5
2017      6
...
2017      51
2017      52 (typically, not guaranteed to be 52 periods)
2018      1
2018      2
2018      3
2018      4
-------------^
2018      5
...

我希望选择2017（5）和2018（4）之间的所有行，我该怎么做？我尝试了几种不同的方法，但无法弄明白。薪酬期通常是1-52，但我不能指望。

Answer 1

一个选项

Select * 
 from YourTable
 Where ([Year]*100)+[PayPeriod] between 201705 and 201804

Answer 2

一般来说，你可以用两个条件来处理这个问题。

declare @yr int = 2018, @period = 5;

select * from t
where
       yr = @yr     and period <= @period
    or yr = @yr - 1 and period >= @period

我不知道你将如何通过截止期，但有许多方法可能是合适的：

-- period number is supplied as an argument
with lp(last_period) as (
    select 4
)
select yr, period
from T cross join lp
where
        yr = year(current_timestamp)     and period <= last_period 
    or  yr = year(current_timestamp) - 1 and period >= last_period;


-- assumes the "last" row in the table is the cutoff
with lp(last_period) as (
    select distinct first_value(period) over (order by yr desc, period desc)
    from T 
)
select yr, period
from T cross join lp
where
        yr >= year(current_timestamp) - 1
    and yr  = year(current_timestamp) or period >= last_period;


-- calculates period based on current date??
with lp(last_period) as (
    select datepart(week, current_timestamp)
)
select yr, period
from T cross join lp
where
        yr = year(current_timestamp)     and period <= last_period 
    or  yr = year(current_timestamp) - 1 and period >= last_period;

Answer 3

如果行数较少，我会回答@JohnCappelletti的回答。它简单易懂。

如果您有大量行，并且需要优化查询以使用索引，那么您希望避免计算您正在搜索的字段（并避免OR条件）< / em>的。因此我会使用像...这样的东西。

SELECT * FROM yourTable WHERE yr = 2016 AND period >= 5 UNION ALL SELECT * FROM yourTable WHERE yr = 2017 AND period < 5

但实际上，我建议更改表格的结构。正如你已经发现，当你将比例分成两个字段时，过滤范围是“尴尬的”。

一种选择可能是使用代表每个支付期开始的DATE字段。

或者可能在每个报告期间都有一个单独的表格......

CREATE TABLE dim_pay_period ( id INT IDENTITY(1,1), start_date DATE, year INT, period INT, -- The 1-52(ish) that you're using year_period INT, -- 201705, for example num_working_days INT -- Just an example... )

然后您的数据表将有一个列“pay_year_period”，如果您需要查找有关该year_period的信息，您可以加入维度表。

SQL Server之间的语句

3 个答案: