How to find what foreign key references an index on table

Question

I have a non clustered index I would like to drop (it is a duplicate of the clustered index). However, it is being used by a foreign key constraint. I would like to be abl

Answer 1

This will tell you the tables, the foreign key and the columns involved:

select f.name
  , parentTable = o.name
  , parentColumn = c.name
  , foreignTable = ofr.name
  , foreignColumn = cfr.name
from sys.foreign_keys f
  inner join sys.foreign_key_columns fc on f.object_id = fc.constraint_object_id
  inner join sys.objects o on fc.parent_object_id = o.object_id
  inner join sys.columns c on fc.parent_column_id = c.column_id
    and o.object_id = c.object_id
  inner join sys.objects ofr on fc.referenced_object_id = ofr.object_id
  inner join sys.columns cfr on fc.referenced_column_id = cfr.column_id
    and ofr.object_id = cfr.object_id
  inner join sys.indexes i on ofr.object_id = i.object_id
where i.name = 'MyIndex'

SQL Fiddle with demo.