Hi,

We can create more than one
relationship between two tables.  Could you tell me a situation where we need two relationships between two tables?

Thanks

Say you have a customers table and a table that represents a transaction between two customers holding two columns with a customer id. The referencing table would need to have two foreign keys pointing on the customerid

  We can create more than one
  relationship between two tables.  Could you tell me a situation where we need two relationships between two tables?

  Thanks

Hi
You can have that kind of relationship but it violates 2nd and 3rd Normal
Forms:

For Eg:
Table_Student
Name Subject-ID Room-Number

Table_Class Room
Subject-ID Subject-Desc Room-Number

was this your question?

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Not necessarily. Suppose we have the following

Create Table Employees
(
    Id Int Primary Key
    , LastName VarChar(25)
    , FirstName VarChar(25)
)

Create Table ManagerStaff
(
    Id Int Primary Key
    , ManagerId Int References Employee(Id)
    , SubordinateId Int References Employee(Id)
    , StartDate DateTime
    , EndDate DateTime
)

I have two relationships to the Employees table yes this is still normalized to
third normal form.


Thomas

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