cancel
Showing results for 
Search instead for 
Did you mean: 
Reply
sdjensen
Solution Sage
Solution Sage

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 involved in creating the files some of them doesn't match the correct syntax. This result in my query to fail.

 

What I am after is some kind of error handling in the query, so the query doesn't stop, but skip the file and then continue. A bonus feature would be an extra table with the filename of those files that failed to be loaded.

 

Have anyone of you done anything similar to this or perhaps have an idea on how to solve it?

 

 

/sdjensen
1 ACCEPTED SOLUTION

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

View solution in original post

7 REPLIES 7
v-shex-msft
Community Support
Community Support

HI @sdjensen,

 

>>All the files should have the same amount of columns - however because humen is involved in creating the files some of them doesn't match the correct syntax.

In my opinion, you can try to add some steps to filter the error records , then merge these filtered records.

Table.RemoveRowsWithErrors

 

BTW, you can also add the 'Data Validation' to columns of your source file if you use the excel files as source.

Excel data validation - regular expressions?

 

Regards,

Xiaoxin Sheng

Community Support Team _ Xiaoxin
If this post helps, please consider accept as solution to help other members find it more quickly.

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.

/sdjensen

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

Community Support Team _ Xiaoxin
If this post helps, please consider accept as solution to help other members find it more quickly.

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.

/sdjensen

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

Community Support Team _ Xiaoxin
If this post helps, please consider accept as solution to help other members find it more quickly.

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

View solution in original post

I know this is old but thanks for sharing the solution you found. I'm in the same scenario.  You dont happen to have a file you can share where this function is operating? I use a lot more DAX than M so its a little difficult to follow.

Helpful resources

Announcements
2022 Release Wave 1 760x460.png

2022 Release Wave 1 Plan

Power Platform release plan for the 2022 release wave 1 describes all new features releasing from April 2022 through September 2022.

Power BI December 2021 Update_carousel 768x460.jpg

Check it Out!

Click here to read more about the December 2021 Updates!

User Group Leader Meeting January 768x460.png

Calling all User Group Leaders!

Don't miss the User Group Leader meetings on January, 24th & 25th, 2022.

Jan 2022 Dev Camp 768x460 copy.png

Power BI Dev Camp- January 27th, 2022

Mark your calendars and join us for our next Power BI Dev Camp!

Top Solution Authors
Top Kudoed Authors