To this end, the integrity constraint
in line 9 expresses that all places must be visited from the starting point given by start/1.
where Ri means the relation, Ii means the integrity constraint
for i [member of] <1,n>; I means global integrity constraints
for all relationships among relations.
A System Prototype for Map Editing and Integrity Constraint
A referential integrity constraint
between relation rn and referenced relation rf implies that a foreign key value in rn should match primary key value in rf.
However, contrary to the schema constraint routine, in the integrity constraint
routine the removal of a subtree (rooted at an update position p) triggers the subtree traversal for searching key and foreign key values involved in the update.
The second constraint, called "the referential integrity constraint
," makes sure that whenever a column in one table derives values from a key of another table, those values must be consistent.
Furthermore, if there is an integrity constraint
Kowalski (1978) suggests that an integrity constraint
is a formula that is consistent with the DDB, but for Reiter (1984) and Lloyd and Topor (1985), an integrity constraint
is a theorem of the DDB.
Partial subsumption is essentially the application of the subsumption algorithm with C as the integrity constraint
and D as the body of a rule that defines a predicate.
Likewise, a referential integrity constraint
would be defined between the INVOICE and the ACCOUNT tables based on that Account_Number value.
Suppose the plane can carry at most 200 passengers, so that the integrity constraint
of the system is res_seats [less than or equal to] 200.