Conditional join with conditions (=, <>) stored in columns

[JVos]

I want to join records in Table A with records in Table B, based on conditions in Table B. How can this be done the easiest way, probably with a SelectRows statement?

Contents of Table A:

ID	Name	Coating	Usage
10	A	F-CT	Commercial
11	A	F-CT	Basic Seed
12	A		Commercial
13	A		Basic Seed
14	A	F+I-CT	Commercial
15	A	F+I-CT	Basic Seed
16	B		Commercial

Contents of Table B:

Name	CoatingCondition	UsageCondition	Outcome
A			O-1
A	= "F+I-CT"		O-2
A		= "Basic Seed"	O-3
A		<> "Basic Seed"	O-4
B			O-5

The match must be on the Name and on the Condition-columns. Note: an empty condition means that condition is not relevant. So for example the first record in Table B will match with all records in Table A where Name = "A".

The expected results are the following:

ID	Name	Outcome
10	A	O-1
10	A	O-4
11	A	O-1
11	A	O-3
12	A	O-1
12	A	O-4
13	A	O-1
13	A	O-3
14	A	O-1
14	A	O-2
14	A	O-4
15	A	O-1
15	A	O-2
15	A	O-3
16	B	O-5

This is the basic code that I think I have to extend (based on PowerQuery(M)agic: Conditional Joins using Table.SelectRows() - P3 (powerpivotpro.com):

let
    TableA = Excel.CurrentWorkbook(){[Name="tblRoute"]}[Content],
    TableB = Excel.CurrentWorkbook(){[Name="tblBAAM"]}[Content],

    TableA_TableB = Table.AddColumn(TableA, "Outcome", each Table.SelectRows(TableB, (Magic) => [RouteName]=Magic[RouteName])),
    Result = Table.ExpandTableColumn(TableA_TableB, "Outcome", {"Outcome"})

in

    Result

[AlB · Accepted solution]

Hi @JVos 

Try this

let
    TableA = Excel.CurrentWorkbook(){[Name="tblRoute"]}[Content],
    TableB = Excel.CurrentWorkbook(){[Name="tblBAAM"]}[Content],
    TableA_TableB = Table.AddColumn(TableA, "Outcome", each Table.SelectRows(TableB,
         
         (Magic) => Magic[Name]=[Name] and (if Magic[CoatingCondition] = null then true else Expression.Evaluate("[Coating]" & Magic[CoatingCondition], [_=_])) 
                and (if Magic[UsageCondition] = null then true else Expression.Evaluate("[Usage]" & Magic[UsageCondition], [_=_])))
    ),    
    Result = Table.ExpandTableColumn(TableA_TableB, "Outcome", {"Outcome"}),
    #"Removed Columns" = Table.RemoveColumns(Result,{"Coating", "Usage"})
in
    #"Removed Columns"

Please mark the question solved when done and consider giving a thumbs up if posts are helpful.

Contact me privately for support with any larger-scale BI needs, tutoring, etc.

Cheers 

[JVos]

@AlB Great! Wonderful! With some minor changes in column names, it worked! Now I'm going to try to understand it...

JVos