自动展开所有具有特定名称的 "Table Columns"

Question

我是编码初学者，不熟悉 "M" 建模语言。我有一个 XML 文件，我想用它在查询编辑器中加载数据。在查询中，我只需要展开具有以下特定名称的 table 列：

查看
查看文件夹
属性：名称

我发现以下 post where they give a function by Chris Webb 用于扩展所有列表（代码下方）。

= (TableToExpand as table, optional ColumnNumber as number) =>
    let
     ActualColumnNumber = if (ColumnNumber=null) then 0 else ColumnNumber,
     ColumnName = Table.ColumnNames(TableToExpand){ActualColumnNumber},
     ColumnContents = Table.Column(TableToExpand, ColumnName),
     ColumnsToExpand = List.Distinct(List.Combine(List.Transform(ColumnContents, each if _ is table then Table.ColumnNames(_) else {}))),
     NewColumnNames = List.Transform(ColumnsToExpand, each ColumnName & "." & _),
     CanExpandCurrentColumn = List.Count(ColumnsToExpand)>0,
     ExpandedTable = if CanExpandCurrentColumn then Table.ExpandTableColumn(TableToExpand, ColumnName, ColumnsToExpand, NewColumnNames) else TableToExpand,
     NextColumnNumber = if CanExpandCurrentColumn then ActualColumnNumber else ActualColumnNumber+1,
     OutputTable = if NextColumnNumber>(Table.ColumnCount(ExpandedTable)-1) then ExpandedTable else ExpandAll(ExpandedTable, NextColumnNumber)
    in
     OutputTable

但是如何只扩展需要的lists/tables？

Answer 1

您应该能够简单地在旧 ColumnsToExpand 行上放置一个过滤器。

即

 TableColumns = //This is the old ColumnsToExpand definition renamed.
     List.Distinct(List.Combine(List.Transform(ColumnContents, each if _ is table then Table.ColumnNames(_) else {}))),
 ColumnsToExpand =
     List.Select(TableColumns, each (_ = "view" or _ = "viewfolder" or _ = "Attribute:name")),

或者像这样在一行中，

 ColumsToExpand = List.Select(List.Distinct(List.Combine(List.Transform(ColumnContents, each if _ is table then Table.ColumnNames(_) else {}))), each (_ = "view" or _ = "viewfolder" or _ = "Attribute:name")),

自动展开所有具有特定名称的 "Table Columns"

Automatically Expand all "Table Columns" with specific name

excel

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