Forum Discussion

Anonymous's avatar
Anonymous
Not applicable
3 years ago
Solved

Add column with blank/zeros in custom function if no data provided

Hi there,   I am looking for some help modifying a function I am working on in Power Query. Currently the function takes a variety of inputs from the user (most optional except for the first one) ...
Need Help
  • Anonymous's avatar
    Anonymous
    3 years ago

    I was able to get the desired output with the following code. The only addition needed was the 

    #"RenameUnitsPC" = if UNITS_PER_CASE = null then Table.AddColumn(#"RenameSKUDesc","UNITS PER CASE", each "0") else Table.RenameColumns(#"RenameSKUDesc",{UNITS_PER_CASE,"UNITS PER CASE"}),

    "Table.AddColumn(#"RenameSKUDesc", "UNITS PER CASE", each "0") to the boolean expression of the columns I wanted included as only zeros if no input was added by the user.

    //If no inputs are provided for UNITS PER CASE, UNIT L, UNIT W, UNIT H, or UNIT WEIGHT, these columns will be included in the resulting table as columns of Zeros

let
//declare a function

ImportAndRename =
(SKU_Column as text, optional SKU_Description as text, optional UNITS_PER_CASE as text, optional UNIT_L as text, optional UNIT_W as text, optional UNIT_H as text, optional UNIT_WEIGHT as text, optional MASTER_CASE_L as text, optional MASTER_CASE_W as text, optional MASTER_CASE_H as text, optional MASTER_CASE_WEIGHT as text, optional CATEGORY as text, optional SUBCATEGORY as text, optional Additional_Column1 as text, optional Additional_Column2 as text, optional Additional_Column3 as text, optional Additional_Column4 as text,  optional Additional_Column5 as text,  optional Additional_Column6 as text, optional Additional_Column7 as text, optional Additional_Column8 as text, optional Additional_Column9 as text, optional Additional_Column10 as text) => let

Optional_SKU_Description = if SKU_Description = null then {} else {SKU_Description},
Optional_UNITS_PER_CASE = if UNITS_PER_CASE = null then {} else {UNITS_PER_CASE}, 
Optional_UNIT_L = if UNIT_L = null then {} else {UNIT_L},
Optional_UNIT_W = if UNIT_W = null then {} else {UNIT_W},
Optional_UNIT_H = if UNIT_H = null then {} else {UNIT_H}, 
Optional_UNIT_WEIGHT = if UNIT_WEIGHT = null then {} else {UNIT_WEIGHT},
Optional_MASTER_CASE_L = if MASTER_CASE_L = null then {} else {MASTER_CASE_L},
Optional_MASTER_CASE_W = if MASTER_CASE_W = null then {} else {MASTER_CASE_W}, 
Optional_MASTER_CASE_H = if MASTER_CASE_H = null then {} else {MASTER_CASE_H},
Optional_MASTER_CASE_WEIGHT = if MASTER_CASE_WEIGHT = null then {} else {MASTER_CASE_WEIGHT},
Optional_CATEGORY = if CATEGORY = null then {} else {CATEGORY}, 
Optional_SUBCATEGORY = if SUBCATEGORY = null then {} else {SUBCATEGORY},
Optional_Columns1 = if Additional_Column1 = null then {} else {Additional_Column1},
Optional_Columns2 = if Additional_Column2 = null then {} else {Additional_Column2},
Optional_Columns3 = if Additional_Column3 = null then {} else {Additional_Column3},
Optional_Columns4 = if Additional_Column4 = null then {} else {Additional_Column4},
Optional_Columns5 = if Additional_Column5 = null then {} else {Additional_Column5},
Optional_Columns6 = if Additional_Column6 = null then {} else {Additional_Column6},
Optional_Columns7 = if Additional_Column7 = null then {} else {Additional_Column7},
Optional_Columns8 = if Additional_Column8 = null then {} else {Additional_Column8},
Optional_Columns9 = if Additional_Column9 = null then {} else {Additional_Column9},
Optional_Columns10 = if Additional_Column10 = null then {} else {Additional_Column10},


#"SelectColumns" = Table.SelectColumns(#"ITEM_INPUT", List.Combine({{SKU_Column}, Optional_SKU_Description, Optional_UNITS_PER_CASE, Optional_UNIT_L, Optional_UNIT_W, Optional_UNIT_H, Optional_UNIT_WEIGHT, Optional_MASTER_CASE_L, Optional_MASTER_CASE_W, Optional_MASTER_CASE_H, Optional_MASTER_CASE_WEIGHT, Optional_CATEGORY, Optional_SUBCATEGORY, Optional_Columns1, Optional_Columns2, Optional_Columns3, Optional_Columns4, Optional_Columns5, Optional_Columns6, Optional_Columns7, Optional_Columns8, Optional_Columns9, Optional_Columns10})),

#"RenameColumns" = Table.RenameColumns(#"SelectColumns", {{SKU_Column, "SKU"}}), 

//UNITS PER CASE, UNIT L, UNIT W, UNIT H and UNIT WEIGHT are created as columns of Zeros in this step if they were not passed as inputs to the function.
#"RenameSKUDesc" = if SKU_Description = null then #"RenameColumns" else Table.RenameColumns(#"RenameColumns",{SKU_Description, "SKU Description"}), 
#"RenameUnitsPC" = if UNITS_PER_CASE = null then Table.AddColumn(#"RenameSKUDesc","UNITS PER CASE", each "0") else Table.RenameColumns(#"RenameSKUDesc",{UNITS_PER_CASE,"UNITS PER CASE"}),
#"RenameUNITL" = if UNIT_L = null then Table.AddColumn(#"RenameUnitsPC","UNIT L",each "0") else Table.RenameColumns(#"RenameUnitsPC",{UNIT_L, "UNIT L"}),
#"RenameUNITW" = if UNIT_W = null then Table.AddColumn(#"RenameUNITL","UNIT W",each "0") else Table.RenameColumns(#"RenameUNITL",{UNIT_W, "UNIT W"}),
#"RenameUNITH"  = if UNIT_H = null then Table.AddColumn(#"RenameUNITW","UNIT H",each "0") else Table.RenameColumns(#"RenameUNITW",{UNIT_H, "UNIT H"}), 
#"RenameUNITWEIGHT" = if UNIT_WEIGHT = null then Table.AddColumn(#"RenameUNITH","UNIT WEIGHT",each "0") else Table.RenameColumns(#"RenameUNITH",{UNIT_WEIGHT, "UNIT WEIGHT"}),
#"RenameMCL" = if MASTER_CASE_L = null then #"RenameUNITWEIGHT" else Table.RenameColumns(#"RenameUNITWEIGHT",{MASTER_CASE_L,"MASTER CASE L"}),
#"RenameMCW" = if MASTER_CASE_W = null then #"RenameMCL" else Table.RenameColumns(#"RenameMCL",{MASTER_CASE_W,"MASTER CASE W"}),
#"RenameMCH" = if MASTER_CASE_H = null then #"RenameMCW" else Table.RenameColumns(#"RenameMCW",{MASTER_CASE_H, "MASTER CASE H"}),
#"RenameMCWeight" = if MASTER_CASE_WEIGHT = null then #"RenameMCH" else Table.RenameColumns(#"RenameMCH",{MASTER_CASE_WEIGHT, "MASTER CASE WEIGHT"}),
#"RenameCat" = if CATEGORY = null then #"RenameMCWeight" else Table.RenameColumns(#"RenameMCWeight",{CATEGORY,"CATEGORY"}),
#"RenameSubCat"= if SUBCATEGORY = null then #"RenameCat" else Table.RenameColumns(#"RenameCat",{SUBCATEGORY,"SUBCATEGORY"})

in #"RenameSubCat", 


//declare Column_Type list
Column_Type = type text
meta
[Documentation.Description = "Please select the SKU column",
Documentation.AllowedValues = Table.ColumnNames(#"ITEM_INPUT")],

//declare custom function type using custom number types
MyFunctionType = type function(
SKU_Column as Column_Type,
optional SKU_Description as Column_Type,
optional UNITS_PER_CASE as Column_Type,
optional UNIT_L as Column_Type,
optional UNIT_W as Column_Type,
optional UNIT_H as Column_Type,
optional UNIT_WEIGHT as Column_Type,
optional MASTER_CASE_L as Column_Type,
optional MASTER_CASE_W as Column_Type,
optional MASTER_CASE_H as Column_Type,
optional MASTER_CASE_WEIGHT as Column_Type,
optional CATEGORY as Column_Type,
optional SUBCATEGORY as Column_Type,
optional Additional_Column1 as Column_Type,
optional Additional_Column2 as Column_Type,
optional Additional_Column3 as Column_Type,
optional Additional_Column4 as Column_Type, 
optional Additional_Column5 as Column_Type, 
optional Additional_Column6 as Column_Type,
optional Additional_Column7 as Column_Type,
optional Additional_Column8 as Column_Type,
optional Additional_Column9 as Column_Type,
optional Additional_Column10 as Column_Type)
as table,

//cast original function to be of new custom function type
ImportAndRenameV2 = Value.ReplaceType(
ImportAndRename,
MyFunctionType)

in 
ImportAndRenameV2

     

Anonymous's avatar
Anonymous
Not applicable
3 years ago

Hi John jbwtp ,

 

The end result is of what you provided is essentially what I am looking for. I swapped the "Expected" and "ChangeTo" in your example as the table created by the code you provided had the wrong column names.

The zero'd columns are definitely what I was after. I am a bit confused how to incorporate that functionality into my function in a way that still allows me to easily pick the other columns I want to take from the original data set. I understand your suggestion of using a list but, because the data set column names are always different, the format of my function originally allows it to be easily applied to the original data table without creating a list of the columns. 

The intention of the function is to be able to be applied directly to the data table and convert that to a table with consistantly named columns.

jbwtp's avatar
jbwtp
Memorable Member
3 years ago

Hi Anonymous,

 

I think you can have tweak it to use for your purpose. This is essentially the function:

 

f = (Data as table, Columns as table) =>
    let 
        ColumnsToTakeFromDataTable = List.Select(Table.ColumnNames(Data), each List.Contains(Columns[Expected], _)),
        CleanUpDataTable = Table.SelectColumns(Data,ColumnsToTakeFromDataTable),
        MissingColumnsNeedToBeForced = List.RemoveItems(Table.SelectRows(Columns, each [Force] = true)[Expected], ColumnsToTakeFromDataTable),
        CompleteTable = List.Accumulate(MissingColumnsNeedToBeForced, CleanUpDataTable, (a, n)=> Table.AddColumn(a, n, each 0, type number)),
        RenameList = List.Transform(Table.ToRecords(Table.SelectRows(Columns, each List.Contains(Table.ColumnNames(CompleteTable), [Expected]))), each {[Expected], [ChangeTo]}),
        RenamedColumns = Table.RenameColumns(CompleteTable,RenameList)
    in
        RenamedColumns,

 

 

This is how you would call it:

 

 Output = f(INPUT_DATA, TableSpecificTranslationTable)

 

 

The Columns table can be table specific, so for each input table you can have column that lists all the required fields against the desired name:

 

You can then select the desired columns (i.e. Expected T1 or Expected T2 with the rest of the table) or modify the function to select is based on the key columns in the INPUT_TABLE or additional text parameter or anything else. The key is that you provide a table-specific translation into the function and it does the rest.

 

Cheers,

John