Overview
When the destination is a database and the flow has multiple source-to-destination transformations — for example, loading into several related tables — the order in which the transformations run can matter.
When two tables are linked by a foreign-key constraint, the parent table must be loaded before the child table. Otherwise the destination raises a Foreign key constraint violation.
How do I fix this?
Disable the Parallel option for all transformations and reorder them so the parent loads first and the child loads next.