怎么计算上个月的第一天和最后一天之间的数据？

我想计算具有固定范围的特定列，但我找不到正确的方法。

DECLARE @FirstDayOfLastMonth DATETIME = dateadd(month, - 1, format(getutcdate(), 'yyyy-MM-01'))
DECLARE @LastDayOfLastMonth DATETIME = EOMONTH(@FirstDayOfLastMonth)

--SELECT SUM(Debit)FROM vGLTransaction_Detail WHERE DatePosted > @FirstDayOfLastMonth AND DatePosted < @LastDayOfLastMonth GROUP BY AcctCode
----This works alone and this is my desired output SELECT AcctCode
,(
SELECT SUM(Debit)
FROM vGLTransaction_Detail
WHERE DatePosted > @FirstDayOfLastMonth
AND DatePosted < @LastDayOfLastMonth
GROUP BY AcctCode
) [Beginning] --i want something like this
,SUM(Debit) [Debit]
,SUM(Credit) [Credit]
,SUM(Credit) [Ending]
FROM dbo.vGLTransaction_Detail
GROUP BY AcctCode