Question Many to Many remove ??

[carl12345]

Hi everyone i have a problem i just started Databases in college and i got a question on homework and i don't understand
Employees
PK EmplID
name
email
phone

services calls
PK CallID
ainProblem
date
resolution

Clients
PK ClientsID
phone
address
city
county
contact

Question:::given the following ERD reproduce the database schema to reflect the removal of the many-many relationship.
I KNOW I SHOULDN'T COME HERE CAUSE IT's HOMEWORK BUT I DONT GET THE QUESTION, ive looked everywhere
even the slightest bit of help(tiny) would be greatly appreciated :banghead::banghead:

 

[Frothingslosh]

We'll need more information before we can even give you hints. The data as you described it has no apparent relationships between tables at all, much less a many-to-many. I assume there's some sort of connection between Employees and Service Calls and another between Service Calls and Clients? If there is, the linking fields (likely FKEmployeeID and FKClientID) seem to be missing from Service Calls.

That said, this is a situation where there SHOULD be a many-to-many relationshiop (of a sort): each employee could, in theory, go on many service calls, and each client could certainly require multiple service calls.

That said, in this case, the only possible reason I can think of offhand to USE that many-to-many would be to pull up a list of all employees who have ever gone on service calls to specific clients.

 

[carl12345]

thanks for reply the erd only has line from one box to another just a straight line i don't get it i don't have to do this in access ive to draw out the solution

 

[carl12345]

the line goes from employees to service calls then straight line down to clients if thats any help

 

[jdraw]

Research Many to Many Relationships Database

Here's a video that may help.

 

[carl12345]

thanks i mostly understand many-to-many but i just don't really understand the question does it ask me to make a many to many relationship ??

 

[jdraw]

i just don't really understand the question does it ask me to make a many to many relationship ??

Many-to-Many Relationships
(from http://r937.com/relational.html )

Two tables are related in a many-to-many (M—M) relationship when for every row in the first table, there can be many rows in the second table, and for every row in the second table, there can be many rows in the first table. Many-to-many relationships can't be directly modeled in relational database programs, including Microsoft Access. These types of relationships must be broken into multiple one-to-many relationships. For example, a patient may be covered by multiple insurance plans and a given insurance company covers multiple patients. Thus, the tblPatient table in a medical database would be related to the tblInsurer table in a many-to-many relationship. In order to model the relationship between these two tables, you would create a third, linking table, perhaps called tblPtInsurancePgm that would contain a row for each insurance program under which a patient was covered (see Figure 5). Then, the many-to-many relationship between tblPatient and tblInsurer could be broken into two one-to-many relationships (tblPatient would be related to tblPtInsurancePgm and tblInsurer would be related to tblPtInsurancePgm in one-to-many relationships).

Figure 5
Figure 5. A linking table, tblPtInsurancePgm, is used to model the many-to-many relationship between tblPatient and tblInsurer.