Application Development and Automation Discussions
Join the discussions or start your own on all things application development, including tools and APIs, programming models, and keeping your skills sharp.
The cardinality (n : m) describes the foreign key relationship with regard to the number of possible dependent records involved (records of the foreign key table) or referred records (records of the check table).
The right side of the cardinality has the following significance:
m = 1
For each record of the check table there is exactly one dependent record.
m = C
For each record of the check table there is at most one dependent record.
m = N
For each record of the check table there is at least one dependent record.
m = CN
For each record of the check table there are any number of dependent records.
The cardinality (n : m) describes the foreign key relationship with regard to the number of possible dependent records involved (records of the foreign key table) or referred records (records of the check table).
The right side of the cardinality has the following significance:
m = 1
For each record of the check table there is exactly one dependent record.
m = C
For each record of the check table there is at most one dependent record.
m = N
For each record of the check table there is at least one dependent record.
m = CN
For each record of the check table there are any number of dependent records.
Bluesky
