In a relational database, a weak entity is an entity that can't be uniquely identified by its own attributes alone, and therefore must use as its primary key both its own attributes and the primary key of an entity it is related to. A weak entity set is indicated by a bold rectangle (the entity) connected by a bold arrow to a bold diamond (the relationship).
All Wikipedia text
is available under the
terms of the GNU Free Documentation License
Search Encyclopedia
Search over one million articles, find something about almost anything!
... (born 970), attempted to colonize Vinland
George Everest, (1790-1866)
F
Matthew Flinders, (1774-1814), first to circumnavigate Australia and Tasmania, extensively ...