根据其他查询的最大值进行过滤

Question

假设我们有这两个表：

table_a

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMlSK1YlWMgKTxmDSBEyagkkzMGmuFBsLAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Column1 = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Column1", Int64.Type}})
in
    #"Changed Type"

table_b

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMlSK1YlWMgKTxmDSBEyagkkzMGkOJi3ApCWYNDSAUBDdhkDtsQA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Column9 = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Column9", Int64.Type}})
in
    #"Changed Type"

目标：

我想过滤 table_b 如 all values equal or less than max value from table_a.

在 R 或 Python 中我会这样做：

# R (data.table)
table_b[Column9 <= max(table_a$Column1)]
# Python (pandas)
table_b[table_b["Column9"] <= table_a["Column1"].max()]

但我不知道如何在 M 中解决这个问题。

Answer 1

在table_b中，添加一个Table.SelectRows引用table_a中Column1的最大值，即List.Max(table_a[Column1])

let Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMlSK1YlWMgKTxmDSBEyagkkzMGkOJi3ApCWYNDSAUBDdhkDtsQA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Column9 = _t]),
#"Changed Type" = Table.TransformColumnTypes(Source,{{"Column9", Int64.Type}}),
#"Filtered Rows" = Table.SelectRows(#"Changed Type", each [Column9] <= List.Max(table_a[Column1]))
in  #"Filtered Rows"

根据其他查询的最大值进行过滤

Filter based on max value of other query

powerquery