Power Query column name as parameter

问题

dear wizards)

I'm trying to create a search function where I could use input: 1. Table for search 2. Column of this Table in which search will run 3. Value to search in the column specified in 2

the function looks like this:

( mTbl as table, mColName as text, mColValue as text) =>

let
    Source = mTbl,
    FilteredTable = Table.SelectRows(Source, each ([ mColName ] =  mColValue )),
    Result = List.Count(FilteredTable[ mColName ])
in
    Result

yet it results in Error:

Expression.Error: The column 'mColName' of the table wasn't found. Details: mColName

Could there be any suggestions? Many thanks in advance

回答1:

Field references like [mColName] are never dynamic, so the code will try to use a field with the name "mColName"; it won't be substituted by the string in parameter mColName.

Instead, you can use: Table.Column(Source,mColName)

回答2:

I had the same need but Table.Columns(Source,mColName) was not working because this is returning a list. In my problem I needed a filtering of the column returned as table.

I solved it as following:

( mTbl as table, mColName as text, mColValue as text) =>

    let
    Source = mTbl,
    Result = Table.SelectRows(Source, each (Record.Field(_, mColName) =  mColValue ))
in
    Result

来源：https://stackoverflow.com/questions/44298772/power-query-column-name-as-parameter