CS457 Syllabus & Progress
SQL: Specifying Constraints on Relations
Constraints
on Relations
The
CREATE TABLE
command can
specify
:
constraints
default values
on
tuples (= data)
in a
relation (table)
Types
of
Constraints
:
Primary Key
constraint
: (see:
click here
)
Candidate (unique) Key
constraint
: (see:
click here
)
Referential integrity
constraint
(see:
click here
)
Attribute domain (range)
not NULL
Default value
for an
attribute