IF DAX for date function

[Jacqueline_Lim]

Hi all,

I would like to look up the [LastTransactionDate] from 'Account' table, and if it's bigger than the [ReactivationDate] from 'DormantAccountReactivation' table, then return value with [LastTransactionDate], else blank.

My DAX is as below:

First Transaction Date = IF('Account'[LastTransactionDate]>'Dormant Account Reactivation'[ReactivationDate],'Account'[LastTransactionDate],blank())

But I received error as below:
A single value for column 'LastTransactionDate' in table 'Account' cannot be determined. This can happen when a measure formula refers to a column that contains many values without specifying an aggregation such as min, max, count, or sum to get a single result.

So I tried below DAX and error was resolved:

First Transaction Date = IF(MAX('Account'[LastTransactionDate])>MAX('Dormant Account Reactivation'[ReactivationDate]),MAX('Account'[LastTransactionDate]),blank())

But the return value was WRONG, it picked up the latest date in the LastTransactionDate column to compare with the latest date in the ReactivationDate column, and return with the latest date in the LastTransactionDate column, which turned out the whole First Transaction Date column became the same date.

Can anyone please help?

[FreemanZ]

Hi @Jacqueline_Lim ,

is the code for a measure or calculated column? How are the two mentioned table related?

[Jacqueline_Lim]

Hi @FreemanZ ,

It's a column. The 2 tables are related via unique client code.

I'm hoping to see the table this way, the first transaction date will have data if the last transaction date is later than reactivation date.

[FreemanZ]

hi @Jacqueline_Lim 

if you use the same code for a measure and plot the same table visual with the measure. it shall work, or?

[Jacqueline_Lim]

@FreemanZ ,

Which one?

What I need is, to lookup the LastTransactionDate in Account table, and check if it is later than the ReactivationDate in DormantAccountReactivation table, if it is, then return value as LastTransactionDate in Account table, else leave it as blank

This DAX gives me error:
First Transaction Date = IF('Account'[LastTransactionDate]>'Dormant Account Reactivation'[ReactivationDate],'Account'[LastTransactionDate],blank())

I've tried creating for a new measure and a new column, both didn't work.

The error I've gotten is:
A single value for column 'LastTransactionDate' in table 'Account' cannot be determined. This can happen when a measure formula refers to a column that contains many values without specifying an aggregation such as min, max, count, or sum to get a single result.

[FreemanZ]

post some data and let us see how it shall work. 

Post Sample Data

UPDATE: @ImkeF wrote a fantastic article for the best way to post data to the forums: https://community.powerbi.com/t5/Community-Blog/How-to-provide-sample-data-in-the-Power-BI-Forum/ba-.... 

[Jacqueline_Lim]

@FreemanZ , I've created an example, does it make sense?

Table 1:

ClientID	LastTransaction Date
1	30/10/2023
2	28/5/2021
3	9/6/2022
4	10/10/2023
5	21/12/2020

Table 2:

ClientID	Reactivation Date
5	1/8/2023
4	2/8/2023
3	3/8/2023
2	4/8/2023
1	5/8/2023

Expected outcome:

ClientID	FirstTransactionDate
1	30/10/2023
2
3
4	10/10/2023
5

[FreemanZ]

or you create a calculated table like:

table = 
ADDCOLUMNS(
    VALUES(Table1[ClientID]),
    "Result",
    VAR _transactiodate = CALCULATE(MAX(Table1[LastTransaction Date]))
    VAR _reactivationdate = CALCULATE(MAX(Table2[Reactivation Date]))
    RETURN
        IF(_transactiodate>_reactivationdate, _transactiodate)
)

it worked like:

[Dangar332]

hi, @Jacqueline_Lim 

if your  table 1 and table 2 are 1:1 then it might work

result1 = 
SWITCH(TRUE(),MAX(Table1[LastTransaction Date])>MAX(Table2[Reactivation Date]),MAX(Table1[LastTransaction Date]),"")

[FreemanZ]

hi @Jacqueline_Lim 

how are table1 and table2 related?

[FreemanZ]

hi @Jacqueline_Lim ,

supposing they are related on ClientID column, then try to plot a table visual with Table1[ClientID] column and a measure like:

measure = 
VAR _transactiodate = MAX(Table1[LastTransaction Date])
VAR _reactivationdate = MAX(Table2[Reactivation Date])
RETURN
    IF(_transactiodate>_reactivationdate, _transactiodate, "")

it worked like:

[Jacqueline_Lim · Accepted solution]

hey @FreemanZ and @Dangar332 ,

Thanks for that! But I think I've finally figured it out.

Below is my final DAX:

First Transaction Date = IF(

LOOKUPVALUE(Account[LastTransactionDate],'Account'[PositionAccountNo],'Dormant Account Reactivation'[ClientCode])>'Dormant Account Reactivation'[ReactivationDate],

LOOKUPVALUE(Account[LastTransactionDate],'Account'[PositionAccountNo],'Dormant Account Reactivation'[ClientCode]),

BLANK())

My problem was, i have to pick up the LastTransactionDate column from another table and then compare it with the ReactivationDate column with my existing table, and return with either LastTransactionDate or BLANK.

It contains 2 conditions: (1) lookup up value, (2) if condition.

I just did this and the data looks fine to me. I hope it doesn't have any underliying issue that I haven't seen yet. *finger crossed*