These functions are deprecated because of their limited use
since the introduction of foreign keys to arbitrary columns in dm 0.2.1.
Use dm_get_all_fks() with table manipulation functions instead.
dm_has_fk(dm, table, ref_table, ...)dm_get_fk(dm, table, ref_table, ...)
A dm object.
A table in the dm.
The table which table will be referencing.
These dots are for future extensions and must be empty.