In Power Query, copies the last non-null value above into each null cell below it (Fill up goes the other way). Empty strings aren't nulls, so convert them first or they stay as they are.
Read more: Microsoft Learn
In the Ultra Transcenders books
Each book explains Fill down in context, with comparison tables and the common traps.
Terms in this definition
- LAST
Restricted to visual calculations, this DAX function reads a value from the final position along one of the visual's axes. Writing INDEX(-1) gives the same result.
- NULL
Marks that a row has nothing in a particular column, as when a person has no middle name. Columns defined NOT NULL can never be left empty.
- CONVERT
Works much like
CAST, changing a value's data type in T-SQL, with the addition of an optional style number; 126, for instance, gives ISO 8601 dates. - FIRST
A DAX function available only inside visual calculations. It fetches the value at the start of one axis of the visual's matrix, which makes it handy for comparing each point with the first; its opposite is LAST.