Forum Discussion
Data Combining Problem
Hi Everyone !
I have got a folder which contains many excel files and i have got a task to combine all of them ..
But The Problem is that the Columns in the Table are not in same order .
Moreover , Many Table have Different Set of Columns Names ..
So I Really Don't Know How To Deal With It .
I Tried Renaming and Reordering .. However , I didn't got the desired result
I Hope Anybody Can Help Me .
Hi aTa_Shaikh,
Thank you for sharing your code and explaining the outcome. I will be clear and constructive: your approach is valid for a different scenario, but it does not address the original problem you described.What is different?- Your code assumes that all tables have the same column names, only in a different order. For that reason, it uses Table.ColumnNames from the first table to apply to the others.
- In the original scenario, the tables have different column names and different sets of columns. When this happens, simply reordering is not enough — you need to normalise the names and ensure that all expected columns exist, even if some are filled with null.
Why our solution differs:- It defines a renaming map to harmonise column names.
- It uses Table.SelectColumns(..., MissingField.UseNull) to align all tables with a standard list of columns.
- It then combines everything with Table.Combine, ensuring consistency.
If you want to adapt your logic to this case, you will need to:- Create a standard list of columns.
- Apply renaming before combining.
- Fill missing columns using MissingField.UseNull.
Below is an annotated version of the custom function. Please ask if you have a specific question
//Input the list of Column Names for the Table that is being processed (ColNames as list)=> let //Read in and Buffer the Lookup Table you created LookupTable=Table.Buffer(Lookups), //Create a List of the Column Names of the Lookup Table which will be the Desired names // for each column Desired=List.Buffer(Table.ColumnNames(LookupTable)), //By adding a custom column to the Lookup table, we can search each row for // each of the Column Names. // When we determine in which column a name is located, we return the column header of that // column which must be the desired name Matches = List.Accumulate( ColNames, {}, (s,c)=> s & {[a=Table.AddColumn(LookupTable,"Match", //Note the Record.FieldValues(_) returns the entries on each row being // processed by the AddColumn method each List.PositionOf(Record.FieldValues(_),c))[Match], b=List.Select(a,each _ >=0), x= if List.IsEmpty(b) then null else {c,Desired{b{0}}}][x]}) in List.RemoveNulls(Matches)Also note that the entire algorithm will handle extraneous columns and missing columns. You will find a missing column by the fact that that merged table will show null instead of a value.
That might mean either that the data is not present at all in the table, OR that you need to add an alias to the relevant column in the Lookup Table.
14 Replies
- ZanquetaSuper User
Hello aTa_Shaikh,
I’m not concerned about the column order, as long as the standard names remain consistent. Do you have a predefined set of column names you expect to combine? Could you share a sample of the headers?
Additionally, should the other sets of column names be disregarded?- ZanquetaSuper User
Ok aTa_Shaikh,
Your files can be combined, but let me know if theses sugestion over renames are possibles:
Logic for Combining
- Import the three tables.
- Rename columns to a common standard:
- Supplier Person Name → Supplier G
- Sales Person or Name → Sales Guy
- Profit → Profit Earning
- Total Money Earned or Total Earning → Total Revenue Generated
- Area or Sales Region → Area Where
- Type Of Day or Day → Day Of Sale
- Select only the required columns.
- Combine all tables using Table.Combine.
- Handle missing columns with MissingField.UseNull.
So, if these could be an approach, adapt and test the script bellow:
let // 1. Import tables (replace with actual file paths) SourceA = Excel.Workbook(File.Contents("C:\Data\a.xlsx"), null, true){[Item="Sheet1",Kind="Sheet"]}[Data], SourceB = Excel.Workbook(File.Contents("C:\Data\b.xlsx"), null, true){[Item="Sheet1",Kind="Sheet"]}[Data], SourceC = Excel.Workbook(File.Contents("C:\Data\c.xlsx"), null, true){[Item="Sheet1",Kind="Sheet"]}[Data], // 2. Rename columns to standard names TableA = Table.RenameColumns(SourceA, { {"Supplier Person Name", "Supplier G"}, {"Sales Person", "Sales Guy"}, {"Total Earning", "Profit Earning"}, {"Total Money Earned", "Total Revenue Generated"}, {"Area", "Area Where"}, {"Type Of Day", "Day Of Sale"} }, MissingField.Ignore), TableB = Table.RenameColumns(SourceB, { {"Supplier", "Supplier G"}, {"Name", "Sales Guy"}, {"Profit", "Profit Earning"}, {"Sales Region", "Area Where"}, {"Day", "Day Of Sale"} }, MissingField.Ignore), TableC = Table.RenameColumns(SourceC, { {"Supplier", "Supplier G"}, {"Name", "Sales Guy"}, {"Profit", "Profit Earning"}, {"Sales Region", "Area Where"}, {"Day", "Day Of Sale"} }, MissingField.Ignore), // 3. Select final columns FinalColumns = {"Supplier G", "Sales Guy", "Profit Earning", "Total Revenue Generated", "Area Where", "Day Of Sale"}, TableA2 = Table.SelectColumns(TableA, FinalColumns, MissingField.UseNull), TableB2 = Table.SelectColumns(TableB, FinalColumns, MissingField.UseNull), TableC2 = Table.SelectColumns(TableC, FinalColumns, MissingField.UseNull), // 4. Combine all tables Result = Table.Combine({TableA2, TableB2, TableC2}) in Result
Please, let me know if it workedIf this response was helpful in any way, I’d gladly accept a 👍much like the joy of seeing a DAX measure work first time without needing another FILTER.
Please mark it as the correct solution. It helps other community members find their way faster (and saves them from another endless loop 🌀.
- aTa_ShaikhFrequent Visitor
ronrsnfld
This is result i am expecting . - aTa_ShaikhFrequent Visitor
Hello Zanqueta ,
Here , I have Shared 3 Different Tables .. All of Tables Have Different Column Names and Different Orders ..
Yes , The Other Sets of column names can be disregarded .- ronrsnfldSuper User
Please show what you expect for a result after you have combined those three tables.
- aTa_ShaikhFrequent Visitor
Zanqueta
Thanks For The Reply .. I Used Your Code and Implemented it my case ..
However , Didn't got the expected result .
Here , is my m code .let
Source = Folder.Contents("Source"),
BinToTables = Table.TransformColumns( Source , {"Content" , (x) => Excel.Workbook(x , true) , type table} ),
ExpandTbl = Table.ExpandTableColumn(BinToTables, "Content", {"Name", "Data", "Item", "Kind", "Hidden"}, {"Name.1", "Data", "Item", "Kind", "Hidden"}),
Columns = Table.ColumnNames( ExpandTbl[Data]{1} ),
Renames = Table.TransformColumns( ExpandTbl ,
{"Data" , (x) =>
Table.RenameColumns( x , List.Zip( {Table.ColumnNames(x) , Columns}) , MissingField.Ignore) , type table} ),
Combine = Table.Combine( Renames[Data] )
in
CombineHere's What I Ended Up As an Output :
I believe Code Takes Care of renaming part .. However , Since the columns are unorder it causes a huge problem.
Usually , When Columns are unorder we use Table.ColumnNames(Table) and make them in perfect order
But , In this case we have different headers for all the columns ..
We Can't Reorder them First and Rename them later ..
- ZanquetaSuper User
Hi aTa_Shaikh,
Thank you for sharing your code and explaining the outcome. I will be clear and constructive: your approach is valid for a different scenario, but it does not address the original problem you described.What is different?- Your code assumes that all tables have the same column names, only in a different order. For that reason, it uses Table.ColumnNames from the first table to apply to the others.
- In the original scenario, the tables have different column names and different sets of columns. When this happens, simply reordering is not enough — you need to normalise the names and ensure that all expected columns exist, even if some are filled with null.
Why our solution differs:- It defines a renaming map to harmonise column names.
- It uses Table.SelectColumns(..., MissingField.UseNull) to align all tables with a standard list of columns.
- It then combines everything with Table.Combine, ensuring consistency.
If you want to adapt your logic to this case, you will need to:- Create a standard list of columns.
- Apply renaming before combining.
- Fill missing columns using MissingField.UseNull.
- ronrsnfldSuper User
Edited to remove extraneous columns
I believe I solved this problem with the following approach, since there does not seem to be any usable algorithm to derive the desired column name from the used name
- Create a Lookup Table that has the desired column name as column headers, and the various aliases listed in the rows below
- The Column names in this table will also be in the desired order.
let Name={"Name","Sales Person","Sales Guy"}, Sales={"Sales","Total Money Earned","Total Revenue Generated"}, Region={"Region","Area","Area Wher"}, Day={"Day","Type Of Day","Day Of Sale"}, Profit={"Profit","Total Earning", "Profit Earning"}, Supplier={"Supplier","Supplier Person Name","Supplier Gr"}, Table=Table.FromColumns({Name,Sales,Region,Day,Profit,Supplier}, type table[Name=text,Sales=text,Region=text,Day=text,Profit=text,Supplier=text]) in TableLookups:
Write a function to "Normalize" the names (and name it: fnNormalizeNames).
The input is a list of the column names for the current table, and the output is list of lists of renaming options.
(ColNames as list)=> let LookupTable=Table.Buffer(Lookups), Desired=List.Buffer(Table.ColumnNames(LookupTable)), Matches = List.Accumulate( ColNames, {}, (s,c)=> s & {[a=Table.AddColumn(LookupTable,"Match", each List.PositionOf(Record.FieldValues(_),c))[Match], b=List.Select(a,each _ >=0), x= if List.IsEmpty(b) then null else {c,Desired{b{0}}}][x]}) in List.RemoveNulls(Matches)- With the above, a script to combine as many tables as you have becomes easier, but you will need to input a list of tables (as in the Source step):
let Source = {TableA, TableB, TableC}, Renames = List.Accumulate( Source, {#table({},{})}, (s,c) => s & { Table.ReorderColumns( Table.RenameColumns(c,fnNormalizeNames(Table.ColumnNames(c))), Table.ColumnNames(Lookups), MissingField.UseNull)}), Combine = Table.Combine(Renames), //Remove Extraneous columns Remove = Table.SelectColumns(Combine, List.Intersect({Table.ColumnNames(Combine), Table.ColumnNames(Lookups)})) in RemoveResults:
- aTa_ShaikhFrequent Visitor
Hi ronrsnfld ,
Can you Please explain me how does this custom function works ?- ronrsnfldSuper User
Below is an annotated version of the custom function. Please ask if you have a specific question
//Input the list of Column Names for the Table that is being processed (ColNames as list)=> let //Read in and Buffer the Lookup Table you created LookupTable=Table.Buffer(Lookups), //Create a List of the Column Names of the Lookup Table which will be the Desired names // for each column Desired=List.Buffer(Table.ColumnNames(LookupTable)), //By adding a custom column to the Lookup table, we can search each row for // each of the Column Names. // When we determine in which column a name is located, we return the column header of that // column which must be the desired name Matches = List.Accumulate( ColNames, {}, (s,c)=> s & {[a=Table.AddColumn(LookupTable,"Match", //Note the Record.FieldValues(_) returns the entries on each row being // processed by the AddColumn method each List.PositionOf(Record.FieldValues(_),c))[Match], b=List.Select(a,each _ >=0), x= if List.IsEmpty(b) then null else {c,Desired{b{0}}}][x]}) in List.RemoveNulls(Matches)Also note that the entire algorithm will handle extraneous columns and missing columns. You will find a missing column by the fact that that merged table will show null instead of a value.
That might mean either that the data is not present at all in the table, OR that you need to add an alias to the relevant column in the Lookup Table.
- aTa_ShaikhFrequent Visitor
Zanqueta ,
Thanks For The Solution 🙂
I was making a silly mistake .. I corrected it and solved the problem .
Also , is it possible to making it a little more dynamic ? Like can we make it more better mainly the column names ?
If we can't , that is also fine ! - RufydaSuper User
I'm glad you found a solution! We're here in the community to support each other.
Regards,
Rufyda Rahma | MIE