Powerbi 在Power BI中清理工作台

我正在尝试将几个Excel文件加载到Power BI中。这些文件非常小（虽然您可以在DAX中执行此操作，但我建议您在查询编辑器中执行此操作

使用ID

列上的左外部联接，将
Correct
表合并到
Bad
表中

展开

Correct

表，仅获取

Colx

列

创建自定义列以拾取所需的值。（添加列>自定义列）

如果[Colx]=null，则[Col1]else[Colx]

如果需要，可以删除

Col1

和

Colx

列，也可以保留它们。如果删除

Col1

，可以将

Col2

列重命名为

Col1

---

如果不希望源表四处浮动，可以在一个查询中执行上述所有操作，如下所示：

let
    BadSource = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMlTSUTJQitWJVjICsfRMwWxjINsIzDIBsnSNlWJjAQ==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [ID = _t, Col1 = _t]),
    CorrectSource = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMlLSUTJUitWJVjIBskyVYmMB", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [ID = _t, Colx = _t]),
    Bad = Table.TransformColumnTypes(BadSource,{{"ID", Int64.Type}, {"Col1", type number}}),
    Correct = Table.TransformColumnTypes(CorrectSource,{{"ID", Int64.Type}, {"Colx", type number}}),
    #"Merged Queries" = Table.NestedJoin(Bad,{"ID"},Correct,{"ID"},"Correct",JoinKind.LeftOuter),
    #"Expanded Correct" = Table.ExpandTableColumn(#"Merged Queries", "Correct", {"Colx"}, {"Colx"}),
    #"Added Custom" = Table.AddColumn(#"Expanded Correct", "Col2", each if [Colx] = null then [Col1] else [Colx]),
    #"Removed Columns" = Table.RemoveColumns(#"Added Custom",{"Col1", "Colx"}),
    #"Renamed Columns" = Table.RenameColumns(#"Removed Columns",{{"Col2", "Col1"}})
in
    #"Renamed Columns"

---

对于这种类型的工作（即清理数据），我通常会在清理坏表后删除正确的表。清理后如何删除/截断表？您可以在高级编辑器中将它们全部加载到同一查询中。这样您就不会留下任何多余的表。请参阅我的编辑。

let
    BadSource = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMlTSUTJQitWJVjICsfRMwWxjINsIzDIBsnSNlWJjAQ==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [ID = _t, Col1 = _t]),
    CorrectSource = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMlLSUTJUitWJVjIBskyVYmMB", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [ID = _t, Colx = _t]),
    Bad = Table.TransformColumnTypes(BadSource,{{"ID", Int64.Type}, {"Col1", type number}}),
    Correct = Table.TransformColumnTypes(CorrectSource,{{"ID", Int64.Type}, {"Colx", type number}}),
    #"Merged Queries" = Table.NestedJoin(Bad,{"ID"},Correct,{"ID"},"Correct",JoinKind.LeftOuter),
    #"Expanded Correct" = Table.ExpandTableColumn(#"Merged Queries", "Correct", {"Colx"}, {"Colx"}),
    #"Added Custom" = Table.AddColumn(#"Expanded Correct", "Col2", each if [Colx] = null then [Col1] else [Colx]),
    #"Removed Columns" = Table.RemoveColumns(#"Added Custom",{"Col1", "Colx"}),
    #"Renamed Columns" = Table.RenameColumns(#"Removed Columns",{{"Col2", "Col1"}})
in
    #"Renamed Columns"