Database relationship
Here in this blog we will look database
relationship in DB2
Here in this blog several types of relationship
can be defined in a database consider the following relationship between
employee and documents
One to many and many to one relationships
An employee can work in only one department;
this relationship is single-valued for employees. On
the other hand, one department can have many employees this relationship is
multi-valued for departments. The relationship
between employees (single-valued) and departments (multi-valued) is a
one-to-many relationship.
To define tables for each one-to-many and each
many-to-one relationship:
Group all the relationship for which the "many
side of the relationship is the same entity and define a single table for all
the relationship in the group
Example the many side of the first and second
relationship is employee table employee is defined.
Table:
Third relationship, "departments" is on the
"many" side, so a department table, DEPARTMENT, is defined.
following tables show these different
relationships.
Employee table:
Table:
