Rollup doesn't work when field is lookup

[Colleen_Briant]

Tables A, B, and C

Table A has a 1 to Many with table B
Table B has a Many to 1 with table C
Table C has a “created at” field, which is linked to on table B via a lookup field

I want to show the max “Created At” of C entries linked to a given A entry.

I get all of the options I think I need in the rollup field creation but then when I select: Rollup, on B, max(lookup field that references C’s created at), nothing happens. All values are blank.

why? How can I fix this?

[Pete]

Hey Colleen – here, I think you’ll want to add a Rollup field with a MAX(VALUES) function to B, referencing the date field on C. Then, you would either want to add a lookup field on A that references the Rollup field on B, or a Rollup field on A – again with a MAX(Values) function – that references the rollup field on B.

Can you let me know if this helps?