Matching two tables with criterias then return matching rows in Power Query without merge function

[Jestii]

Hi, I have this problem 

Have several tables that I need to try to combine in one.
Main table = OLRR

Second table = OLMPDirekta

OLRR and OLMPDirekta I want to create a custom column called OLNyResultat in OLRR and the code should be something like this "if CostType = Absorption (DL) then match Date and CostCenter columns between OLRR and OLMPDirekta and return column DiffNyOLMPDirekta from OLMPDirekta"

the code I have so far with help from GTP is this 

"if [CostType] = "Absorption (DL)" then
let
matchingRows = Table.SelectRows(OLMPDirekta, each [Date] = [Date] and [CostCenter] = [CostCenter]),
result = if Table.RowCount(matchingRows) > 0 then matchingRows{0}[DiffNyOLMPDirekta] else null
in
result
else null"

But the problem here is that it's not returning the right answer except on the first match. 

Table OLMPDirekta

Result in OLRR from the code above 

It gives me result from 202301 which was 2 to all other months 202302, 202303 etc but these should be 1

Any ideas on how to make this work? 

[slorin]

Hi,

try

(x) => if [CostType] = "Absorption (DL)" then
let
matchingRows = Table.SelectRows(OLMPDirekta, each x[Date] = [Date] and x[CostCenter] = [CostCenter]),
result = if Table.RowCount(matchingRows) > 0 then matchingRows{0}[DiffNyOLMPDirekta] else null
in
result
else null

or

(x) => if [CostType] = "Absorption (DL)" then
List.First(
  Table.SelectRows(OLMPDirekta, each x[Date] = [Date] and x[CostCenter] = [CostCenter])[DiffNyOLMPDirekta],
  null)
else null

Stéphane

[Jestii]

Hi, 

When I try both of the codes I get a function result. 
When I click on it I get this popup 

I click Ok without typing in anything and the result is this