Operators in Power Query M

[Sergec67]

Hi,

I can use the operators = and <> between two dates.  But I get an error when I use <, >, >= or <=.  I have both my fields are a Date data type.  

Expression.Error: We cannot apply operator < to types List and Date.
Details:
Operator=<
Left=[List]
Right=2021-05-31

[BA_Pete]

Hi @Sergec67 ,

Power Query quite clearly thinks that one of your dates is actually a list:

You need to ensure that both columns only contain dates in every row.

Pete

[Sergec67]

Every row only have dates.

I think I found my problem. Even if it's a table containing only one row, I still need to identify that row. Without identifying the row it reads it has a list.

Thanks

[BA_Pete · Accepted solution]

Are you trying to apply this comparison across different tables? If you are then, yes, you will need to provide row context for the calculation for the remote table.

If you're making the comparison across two columns in the same table then the row context should be implicit, and there's another issue at play.

Pete