工作需要，想用 power query 作一个 现金日记账，但始终实现不了，请大神帮忙

拼凑了一个，步骤应该可以优化下。

let
    源 = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMjIwMtA31DdU0lF6NmXb09alFRUVQLahkbGJnoU5kKUUqwNXZYSmysjYEE2FMVjF+qftuyAqgMjYxBRZhQmmCiMDA2QVpuhuMQACNHvM0F2CqcQc0yITUxSnWGBxiqEhinfA4TJnzbM5HU839L9YtxCiSik2FgA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [日期 = _t, 摘要 = _t, 借 = _t, 贷 = _t]),
    更改的类型 = Table.TransformColumnTypes(源,{{"日期", type date}, {"摘要", type text}, {"借", type number}, {"贷", Int64.Type}}),
    清除null值 = Table.ReplaceValue(更改的类型,null,0,Replacer.ReplaceValue,{"借","贷"}),
    求值表 = Table.RemoveLastN(清除null值),
    借贷表 = Table.SelectColumns(求值表,{"借","贷"}),
    余额 = List.Skip(
                List.Accumulate(
                    Table.ToRows(借贷表),{0}, (state, current) =>state&{List.Sum({List.Last(state)}&{List.First(current)-List.Last(current)})})),
    小计 = Table.FromColumns(
                Table.ToColumns(更改的类型)&{余额},Table.ColumnNames(源)&{"余额"}),
    结果 = Table.ReplaceMatchingRows(小计,{Table.Last(小计),Record.Combine({Table.Last(小计),[借=List.Sum(List.RemoveLastN(小计[借])),贷=List.Sum(List.RemoveLastN(小计[贷])),余额=List.Last(余额)]})})
in
    结果

被余额和 结果这两步卡住了，能否细讲下这两步。

试试List.Generate,加载20万行还是很快的

let
    源 = Excel.CurrentWorkbook(){[Name="表1"]}[Content],

    gen = let lst = List.Buffer(Table.ToRows(源)), 
                n = List.Count(lst)

           in List.Generate( ()=>{{},"",0,0,0,0}, //{结果list，月份比较值，累计值，借方合计，贷方合计，索引}
                             each _{5}<=n,
                             each let l = lst{_{5}}?,
                                      c = if l=null then {} else l,
                                      m = Date.Month(c{0}?), 
                                      s = _{2}+List.Sum({c{2}?,c{3}?*-1}) 

                                   in if m=_{1} then { {c&{s}},m,s,List.Sum({_{3},c{2}?}),List.Sum({_{4},c{3}?}),_{5}+1}
                                      else {{{"","本月合计",_{3},_{4},_{2}},c&{s}},m,s,c{2}?,c{3}?,_{5}+1},
                             each _{0} ),

    rlt = #table(Table.ColumnNames(源)&{"余额"}, List.Skip(List.Combine(gen)))
in
    rlt

左表变成右表

按月分组，聚合求本月合计，然后插入到原表中

3楼，这个c和s 分别代表什么？