Circular dependency was detected when use Calculated+Firstnonblank

[Anonymous]

Hi Experts,

Hope somone could help me understand this circular dependency error. I'm running a test, the table blelow is very simple, only have two columns: ID is number, and Time is datetime. I created a calcuated column named First_Time using Calcuate function. The problem I could not understand is that why when the Firstnonblank refers to the time (datetime type) column itself, the circular dependency error would happened, but when it refers to a specific date('time'.[day]), the error disappeared.

The DAX First_Time might meaningless, but I really want to understand how Calcuate and Firstnonblank works in this situation.

Thanks in advance

[Anonymous · Accepted solution]

HI @Anonymous,

I think this issue may related to time intelligence feature.

AFAIK, time intelligence will generate a hidden calendar table based on date/time column to expand hierarchy tree for this column.

Firstnonblank function will also loop through current table, so I think it's calculate logic may conflict with hidden calendar table generate, so power bi shows circular dependency error.

In addition, you can also take a look at below link which told about circular dependency issue:

Understanding Circular Dependencies in Tabular and PowerPivot

Regards,

Xiaoxin Sheng

[Anonymous]

Hi Xiaoxin, Thanks a lot for your help. If the date/time column is a calendar table in the backend, it would make sense to explain this circular dependency issue.