Forum Discussion

Solution Sage

8 years ago

Solved

Error handling in loading files from folder

I have a folder with aprox 2000 (and more is added weekly) similar files, that I want to load into a single table. All the files should have the same amount of columns - however because humen is ...

Need Help

sdjensen

8 years ago

I found a solution for this and wanted to share it:

I created a function to handle the load of the individual Excel sheet. I then use this funtion in to individual queries. One to load the data from the files and one that will return the file name of the files that are unable to be processed by the funtion.

The function look like this:

(sourceFile as text) as table =>
let
    Source = Excel.Workbook(File.Contents(sourceFile), null, true),
    ExpandData = Table.ExpandTableColumn(
                Source, 
                "Data", 
                {"Column1", "Column2", "Column3", "Column4", "Column5", "Column6", "Column7", "Column8", "Column9", "Column10", "Column11", "Column12", "Column13", "Column14", "Column15"}, 
                {"Column1", "Column2", "Column3", "Column4", "Column5", "Column6", "Column7", "Column8", "Column9", "Column10", "Column11", "Column12", "Column13", "Column14", "Column15"}
            ),
    AddRowNumber = Table.AddIndexColumn(ExpandData, "Row", 0, 1),

    //Remove Rows with only Nulls
    AddColumnRowWithData = Table.AddColumn(AddRowNumber, "RowWithData", each 
                if [Column1] = null
                    and [Column2] = null
                    and [Column3] = null
                    and [Column4] = null
                    and [Column5] = null
                    and [Column6] = null
                    and [Column7] = null
                    and [Column8] = null
                    and [Column9] = null
                    and [Column10] = null
                    and [Column11] = null
                    and [Column12] = null
                    and [Column13] = null
                    and [Column14] = null
                    and [Column15] = null
                then "Empty Row"
                else "Row with data"
            ),
    RemoveRowsWithNoData = Table.SelectRows(AddColumnRowWithData, each ([RowWithData] = "Row with data")),
    RemoveColomnRowWithData = Table.RemoveColumns(RemoveRowsWithNoData, {"RowWithData"}),

    //Remove Columns with No Name
    TransposeTable = Table.Transpose(RemoveColomnRowWithData),
    RemoveColumnsWithNoName = Table.SelectRows(TransposeTable , each ([Column1] <> null)),
    TransposeTable2 = Table.Transpose(RemoveColumnsWithNoName),

    PromoteHeaders = Table.PromoteHeaders(TransposeTable2, [PromoteAllScalars=true]),
    RenameColumn = Table.RenameColumns(PromoteHeaders,{{"0", "Row"}})

in
    RenameColumn

The code for returning a list of files with errors:

let
    FilePath = fnGetParameter("File Path"),
    Source = Folder.Files(FilePath),
    RemoveOtherColumns = Table.SelectColumns( Source, {"Name", "Folder Path"}),
    CallFunction = Table.AddColumn(RemoveOtherColumns, "LoadAllFiles", each fnLoadFiles([Folder Path]&[Name])),
    KeepFilesWithErrors = Table.SelectRowsWithErrors(CallFunction, {"LoadAllFiles"}),
    RemoveColumns = Table.RemoveColumns(KeepFilesWithErrors ,{"Folder Path", "LoadAllFiles"})
in
    RemoveColumns

sdjensen

Solution Sage

8 years ago

It's not errors on a single row - it's errors like where some of the files have more columns so data is not in the same columns as the correct syntax - this breaks the load, so can't really remove error rows, because it's not single rows that returns the error, but the file itself and as I said that stops the import.

Anonymous

Not applicable

8 years ago

HI sdjensen,

If your tables contains the different structure or column index, I think you need to format them before merge these table.
I don't think it will autoformat your source data.

For example: Use Table.SelectColumns function to find out speicfic columns and index.

Table.Combine

Returns a table that is the result of merging a list of tables. The tables must all have the same row type structure.

Regards,

Xiaoxin Sheng

sdjensen

Solution Sage

8 years ago

As I wrote in my initial post there is a lot of files and manually going through all of them would be an almost impossible task - hence my request for a function that could return the filename of files that fail to load in a different table/list.

Then I could return this list to the involved staff and ask them to handle the files with errors.

Table.SelectColumn will not solve my problem - I can't be sure that the columns is named the same.

Anonymous

Not applicable

8 years ago

Hi sdjensen,

For your scenario, I'd like to suggest you to use programming languages to deal with these data validation and error handling, then output the formatted data. (I think it will be more simply than power query)

Finally, you can use power bi to import these analysis/formatted data.

Regards,

Xiaxoin Sheng

sdjensen

Solution Sage

8 years ago

I found a solution for this and wanted to share it:

The function look like this:

(sourceFile as text) as table =>
let
    Source = Excel.Workbook(File.Contents(sourceFile), null, true),
    ExpandData = Table.ExpandTableColumn(
                Source, 
                "Data", 
                {"Column1", "Column2", "Column3", "Column4", "Column5", "Column6", "Column7", "Column8", "Column9", "Column10", "Column11", "Column12", "Column13", "Column14", "Column15"}, 
                {"Column1", "Column2", "Column3", "Column4", "Column5", "Column6", "Column7", "Column8", "Column9", "Column10", "Column11", "Column12", "Column13", "Column14", "Column15"}
            ),
    AddRowNumber = Table.AddIndexColumn(ExpandData, "Row", 0, 1),

    //Remove Rows with only Nulls
    AddColumnRowWithData = Table.AddColumn(AddRowNumber, "RowWithData", each 
                if [Column1] = null
                    and [Column2] = null
                    and [Column3] = null
                    and [Column4] = null
                    and [Column5] = null
                    and [Column6] = null
                    and [Column7] = null
                    and [Column8] = null
                    and [Column9] = null
                    and [Column10] = null
                    and [Column11] = null
                    and [Column12] = null
                    and [Column13] = null
                    and [Column14] = null
                    and [Column15] = null
                then "Empty Row"
                else "Row with data"
            ),
    RemoveRowsWithNoData = Table.SelectRows(AddColumnRowWithData, each ([RowWithData] = "Row with data")),
    RemoveColomnRowWithData = Table.RemoveColumns(RemoveRowsWithNoData, {"RowWithData"}),

    //Remove Columns with No Name
    TransposeTable = Table.Transpose(RemoveColomnRowWithData),
    RemoveColumnsWithNoName = Table.SelectRows(TransposeTable , each ([Column1] <> null)),
    TransposeTable2 = Table.Transpose(RemoveColumnsWithNoName),

    PromoteHeaders = Table.PromoteHeaders(TransposeTable2, [PromoteAllScalars=true]),
    RenameColumn = Table.RenameColumns(PromoteHeaders,{{"0", "Row"}})

in
    RenameColumn

The code for returning a list of files with errors:

let
    FilePath = fnGetParameter("File Path"),
    Source = Folder.Files(FilePath),
    RemoveOtherColumns = Table.SelectColumns( Source, {"Name", "Folder Path"}),
    CallFunction = Table.AddColumn(RemoveOtherColumns, "LoadAllFiles", each fnLoadFiles([Folder Path]&[Name])),
    KeepFilesWithErrors = Table.SelectRowsWithErrors(CallFunction, {"LoadAllFiles"}),
    RemoveColumns = Table.RemoveColumns(KeepFilesWithErrors ,{"Folder Path", "LoadAllFiles"})
in
    RemoveColumns

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Error handling in loading files from folder

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