## Chapter 16 Disconnected Tables: Banding

A dedicated forum to help people when working through the book "Learn to Write DAX"
Krishna
Posts: 5
Joined: Sat Dec 16, 2017 1:04 am

### Chapter 16 Disconnected Tables: Banding

Hi,

i followed the steps mentioned in the book for Using BANDING but i am getting the issue in creating the calculated field without error

Formula (created in Customers table)
ROUNDDOWN((DATE(YEAR(TODAY()),MONTH(TODAY()),DAY(TODAY()))-Customers[BirthDate])/365,0) in calculated column of customers table
Age Group:=CALCULATE(VALUES(AgeBands[Band]),FILTER(AgeBands,Customers[Age]>=AgeBands[Low] && Customers[Age] < AgeBands[High]))

Error
Calculation error in measure 'Customers'[Age Group]: The value for column 'Age' in table 'Customers' cannot be determined in the current context. Check that all columns referenced in the calculation expression exist, and that there are no circular dependencies. This can also occur when the formula for a measure refers directly to a column without performing any aggregation--such as sum, average, or count--on that column. The column does not have a single value; it has many values, one for each row of the table, and no row has been specified.

thanks
Krishna

P3Tom
Posts: 6
Joined: Tue Jan 09, 2018 4:20 pm

### Re: Chapter 16 Disconnected Tables: Banding

For starters, since TODAY() is a date, you could simplify your calculated column's formula for Age:

Age =
IF (
NOT ( ISBLANK ( Customers[BirthDate] ) ),
ROUNDDOWN ( ( TODAY () - Customers[BirthDate] ) / 365, 0 )
)

Also, I would say that Age Group is probably for a calculated column, since the measure is missing a row context for Customers[Age] which would be available in a calculated column of the Customers table.

Krishna
Posts: 5
Joined: Sat Dec 16, 2017 1:04 am

### Re: Chapter 16 Disconnected Tables: Banding

calculated column Age not missing but still getting Error. followed the steps as described in the book but still Error.

RamanaV
Posts: 14
Joined: Thu Oct 19, 2017 12:57 pm

### Re: Chapter 16 Disconnected Tables: Banding

Age Group is defined as a calculated column in the book.
So, your formula is as in the book, but with Age Group:= in the formula bar, which is understood as a measure and hence is not correct.
Just add another column, the way you did for Age column, type the formula in formula bar, and then rename the new calculated column as Age Group.