I'm not sure if a parameter query will do this (only type I know). I have a db with field plants: and field: reject number. I want to create a report that will count reject number seperated by plant. How would you accomplish this?

Use Sorting/Grouping on the report, Group by plant

Do you mean, sum the rejects by plant?

Select Plant, Sum(RejectAmt) As SumOfRejects
From YourTable
Group By Plant;