I have a table that is Imported from MS SQL. The table data gets refreshed when the PBIX file is opened. The minimalist data looks like this:

first of all, the main problem is that I want to calculate the amount of rows related in the table crffe_clientcheckinlog with crffe_projects, here you have the model:

I am having an issue where I don’t know where to start if I am honest.

i have the table

I would like to create a column in Power BI that looks at column B or C and records column D, but only when its the first time that the given identifier in column B or C has occurred – after that it would give null (this desired result is shown in column E). I cannot simply remove duplicated in column B or C because fields like column F have multiples off of a single column B or C identifier (there are many additional columns after this I am just showing a small piece of relevant data).