从列表格式以表格格式显示工资历史记录？

Question

我确信这对于 SQL 的铁杆极客来说不是一个难题，但我需要一些帮助。这适用于 SQL Server 2000（继承的项目！）。

我有一张如下所示的工资表：

EmployeeID  |  EffectiveDate  | Salary
1           |   2/1/2011      | 500
1           |   6/1/2011      | 600
1           |   12/1/2011     | 650

我需要创建一个查询，该查询将按月输出给定年份的这些薪水。所以输出会是这样的

EmployeeID  | Jan | Feb | Mar | Apr | Apr | May | Jun | Jul | Aug | Sept | Oct | Nov | Dec
1           | 500 | 500 | 500 | 500 | 500 | 500 | 600 | 600 | 600 | 600  | 600 | 600 | 650

我知道必须有一种方法可以使用 SQL 有效地做到这一点，但我似乎无法做到这一点。显然，我会用 SQL 命名上面的月份列，例如 SELECT EmployeeID, 'Jan' AS Jan, 'Feb' AS Feb, 等等，但语句的其余部分更难，因为我正在寻找范围。

Answer 1

由于您使用的是 SQL Server 2000，它没有 PIVOT 函数，因此您必须使用聚合函数和 CASE 语句来复制它。类似这样：

select  employeeid,
  sum(case when DatePart(Month, EffectiveDate) = 1 then Salary end) as Jan,
  sum(case when DatePart(Month, EffectiveDate) = 2 then Salary end) as Feb,
  sum(case when DatePart(Month, EffectiveDate) = 3 then Salary end) as Mar,
  sum(case when DatePart(Month, EffectiveDate) = 4 then Salary end) as Apr,
  sum(case when DatePart(Month, EffectiveDate) = 5 then Salary end) as May,
  sum(case when DatePart(Month, EffectiveDate) = 6 then Salary end) as Jun,
  sum(case when DatePart(Month, EffectiveDate) = 7 then Salary end) as Jul,
  sum(case when DatePart(Month, EffectiveDate) = 8 then Salary end) as Aug,
  sum(case when DatePart(Month, EffectiveDate) = 9 then Salary end) as Sep,
  sum(case when DatePart(Month, EffectiveDate) = 10 then Salary end) as Oct,
  sum(case when DatePart(Month, EffectiveDate) = 11 then Salary end) as Nov,
  sum(case when DatePart(Month, EffectiveDate) = 12 then Salary end) as Dec
from  yourtable
group by employeeid

见SQL Fiddle with Demo

编辑，根据您上面的 cmets 将值从一个月转移到下一个月，这里有一个可能适合您的解决方案。

declare @query as nvarchar(max) = '',
  @rowcount as int = 1,
  @pivotrow as int,
  @currentMonthSalary as int = 0,
  @priorMonthSalary as int = 0,
  @employeeid int 

select distinct effectivedate
into #colspivot
from yourtable

while @rowcount <= 12 -- loop thru each month
  begin

    set @pivotrow = (select top 1 datepart(month, effectivedate)
                        from #colspivot
                        order by datepart(month, effectivedate))

    select @currentMonthSalary = salary, @employeeid = EmployeeID
            from yourtable
            where datepart(month, effectivedate) = @pivotrow

    if @pivotrow = @rowcount
        begin
            insert into FinalData (employeeid, effectivemonth, salary)
            select @employeeid, cast(DateName(month, DateAdd(month, @pivotrow, 0) -1) as varchar(3)), @currentMonthSalary

            set @query = @query + ', sum(case when effectivemonth = ''' +  cast(DateName(month, DateAdd(month, @pivotrow, 0) -1) as varchar(3)) + ''' 
                                        then ' + cast(@currentMonthSalary as varchar(10)) + ' end) as '+ cast(DateName(month, DateAdd(month, @pivotrow, 0) -1) as varchar(3))

            delete from #colsPivot where datepart(month, effectivedate) = @pivotRow

            set @priorMonthSalary = @currentMonthSalary
        end
    else
        begin
            insert into FinalData (employeeid, effectivemonth, salary)
            select @employeeid, cast(DateName(month, DateAdd(month, @rowcount, 0) -1) as varchar(3)), @priorMonthSalary

            set @query = @query + ', sum(case when effectivemonth = ''' + cast(DateName(month, DateAdd(month, @rowcount, 0) -1) as varchar(3)) + '''  
                        then ' +  cast(@priorMonthSalary as varchar(10)) + ' end) as '+cast(DateName(month, DateAdd(month, @rowcount, 0) -1) as varchar(3))
        end

    if @rowcount <= 12
      set @rowcount = @rowcount + 1
  end

set @query = 'select employeeid '+ @query 
              + ' from FinalData group by employeeid;'

exec(@query) 

见SQL Fiddle with Demo。在循环创建 sql 语句时，我创建了一个新表 FinalData 来存储每个月的数据。

Answer 2

试试这个查询：

Select  EmployeeID, [Jan],[Feb],[Mar],[Apr],[May],[Jun],[Jul],[Aug],[Sep],[Oct],[Nov],[Dec]
From
(
    Select EmployeeID, CAST(DateName(MONTH,EffectiveDate) as varchar(3)) as Mon, Salary
        From Employees

) as SourceTable

PIVOT
(
    Sum(Salary)
    For Mon in ( [Jan],[Feb],[Mar],[Apr],[May],[Jun],[Jul],[Aug],[Sep],[Oct],[Nov],[Dec] )
) as PivotTable

它产生的结果与您在输出样本中显示的结果完全相同。