Small confuse of ERDiagram connection

[ryainad]

Hi, everybody.



I've started to draw ERDiagram.



Now I'm confused: What is the defference if I connect country to address and city to country. (interchange city and country)



What I need to do is to create list of values for country and city, where I can choose country and than I will have list of cities of that country.

It seems easy ...

[recyan]

Till someone comes along :
Can an employee have more than 1 address ?
What does Address_Type indicate ?
How is the Employee & his / her address related in the ERD that you have shown ?
The City_ID & not the Country_ID in the Address record, to me, appears right.

Thanks

[ryainad]

Till someone comes along :
Can an employee have more than 1 address ?
What does Address_Type indicate ?

We have to record both of addresses, because we have situations when somebody has permanent and temporary address (it means I work in one city but all my family in other city or address), secondly we have situations when few people from the same family work in a company. So address_type has 2 values: permanent and temporary.

How is the Employee & his / her address related in the ERD that you have shown ?

Employee & address related through the address_type. I made it after normalisation because it was many-to-many connection

The City_ID & not the Country_ID in the Address record, to me, appears right.

When I tried to fill tables from Country table it works fine, but I have a confusion with filling address from employee table.
I made it as a LOV and I got full values of cities.
Does anybody know some links where I can find how to make forms with list of related values?

[recyan]

1) If I have understood correctly, if 2 Employees have the same address, you are storing the Address as common to both. I personally would prefer to store each Employees address seperately against that particular Employee.
2) Still unable to see the relationship between an Employee & his Address. Address_Type, if I have understood correctly has only values of Temporary & Permanent.
3) The way I see it :

tblEmployee
EmployeeID - PK
......

tblAddresses
AddressID - PK
Address
City_ID - FK
AddressType_ID - FK
Employee_ID - FK

Thanks

[ryainad]

Thank you, recyan.

I've changed my diagram.

[recyan]

Don't know, if my thoughts were helpful or not, but all the same glad that you are moving ahead.
In case, required, you may post your latest ERD & some-one else might be able to give more inputs.

Thanks