Power Query - Check all Columns

[Aquila]

Every month, I need to perform a repetitive process, for which I need to verify that all the necessary columns are found in the table of origin. For example, in a table I only need the following columns: Employee, payment and discount, but sometimes the discount column does not come in the source table, so I need to create that column with a value in zero. In short, I need to create a column depending on whether it is not included in my original table. I hope you understand. Thanks a lot.

 

[Chihiro]

What is the source? Is it Excel File? Or database server?

If Excel file, you'd probably need to use "try... otherwise" syntax.

try <code for when there is discount column, that generates error when there isn't> otherwise <code that's used to generate column with zero value>

Have a read of following links.
https://msdn.microsoft.com/query-bi/m/errors
https://msdn.microsoft.com/query-bi/m/error-handling

If SQL server, handle it on native query side.

 

[Aquila]

Ok, it's an Excel table. Thank a lot.

 

[r2c2]

@Aquila... For excel file, you can also add this "Discount" column if doesn't exit using either IF then or try otherwise constructs like below.

=if Table.HasColumns(#"output table", "Discount") then #"output Headers" else Table.AddColumn(#"output Headers", "Discount", each 0),

= try Table.AddColumn(#"output table", "Discount", each 0) otherwise #"output table"

You can insert either of these as a step in your query. Not #"output table" is the previous step. So rename accordingly.