Database Reference
In-Depth Information
in both directions, meaning that an employee must have at least one pay receivable associ-
ated with it, and a Pay receivable must have at least one Employee associated with it. Put-
ting this all together, we can read the relationship between the Employee and Pay entities
as "one employee has one and only one associated pay receivable, and one pay receivable
has one and only one associated employee ."
Following figure shows an example of a typical one-to-one relationship. In this figure, Em-
ployee is the parent table and Pay Receivable is the child table. A single record in the Em-
ployee table can be related to only one record in the Pay Receivable table, and a single
record in the Pay Receivable table can be related to only one record in the Employee table.
Both the tables are linked together by Employee ID is indeed the primary key in both tables.
