Forum Discussion
Table and column
waleed111 , Because selectcolumns return table. And when you create a new column it expects a new column value only one unique value. So new table it works and New columns it gives an error
https://docs.microsoft.com/en-us/dax/selectcolumns-function-dax
https://www.youtube.com/watch?v=TtkdZ2jbffA
New table is working because it expects a table
table = SELECTCOLUMNS('List View', "inventory", 'List View'[Date-Time of Entry in Inventory])
This function can now return a new column
Column = maxx(SELECTCOLUMNS('List View', "inventory", 'List View'[Date-Time of Entry in Inventory]),[Date-Time of Entry in Inventory])
2 Replies
- amitchandakSuper User
waleed111 , Because selectcolumns return table. And when you create a new column it expects a new column value only one unique value. So new table it works and New columns it gives an error
https://docs.microsoft.com/en-us/dax/selectcolumns-function-dax
https://www.youtube.com/watch?v=TtkdZ2jbffA
New table is working because it expects a table
table = SELECTCOLUMNS('List View', "inventory", 'List View'[Date-Time of Entry in Inventory])
This function can now return a new column
Column = maxx(SELECTCOLUMNS('List View', "inventory", 'List View'[Date-Time of Entry in Inventory]),[Date-Time of Entry in Inventory])
- Greg_DecklerCommunity Champion
waleed111 - There are three primary kinds of things that you can create in Power BI
- Column
- Measure
- Table
Columns and Measures formulas need to return single value (a scalar) while tables formulas need to return a table of values. When you are having problems with DAX formulas like this, it is always good to check the documentation:
https://docs.microsoft.com/en-us/dax/selectcolumns-function-dax
Here you can see:
Return value
A table with the same number of rows as the table specified as the first argument. The returned table has one column for each pair of <name>, <scalar_expression> arguments, and each expression is evaluated in the context of a row from the specified <table> argument.
Therefore, for the column formula, you will need to aggregate the table or perform some calculation that returns a scalar value, like wrapping that statement with a COUNTROWS function or one of the X iterators like SUMX, AVERAGEX, etc.