Relationship problem

Hi All... Two of my tables are:

Users - primary key is UserId, an int with identity turned on.

Messages - has a column named UserId that references the same in Users.

I'm using Visual Studio 2005 against a SQL 2005 database.

Using both the diagram tool and table data, I'm trying to set up the relationship implied above and am getting the following error:

Users table saved successfully.

Messages table

- unable to create relationship 'FK_Messages_UserId'.

The ALTER TABLE statement conflicted with the FOREIGN KEY constraint 'FK_Messages_UserId'. The conflict occurred in database 'XXXX', table 'dbo.Users', column 'UserId'.

I've done several other similar relationships without incident. But this one (and one or two others) refuse to work. I'm a bit of newbie with these rascals, so that doesnt help much... Any ideas what this things trying to tell me? Thanks! -- Curt

You might already have entries in your child table which have no parent entry in the parent table.

HTH, Jens K. Suessmeyer.

http://www.sqlserver2005.de|||

Hi Jens... Thanks for the reply. You threw me a little at first on your use of "parent" and "child", but yeah you nailed it. To try and tie those terms to the tables in my original post, I had some records in Messages (child) that referenced a primary key that did not exist in Users (parent). Geez, these FKs really help us keep a clean house, dont they... Thanks again!! Curt

Relational Database design problem

Hi,

I have a very important question about the database design. Suppose that I have a table named as tblPerson with the following Fields.

tblPerson:
--------
PersonID
PersonName

And I have a another table that has the Person Credit card Information:

tblPersonCreditCard:
---------

CreditCardID
PersonID
CreditCardTypeID

And Another table which contains the type of creditcards:

tblCreditCardsType:
----------

CreditCardTypeID
CardName

NOTE: Suppose CreditCardTypeID 1 = "MasterCard", 2 = "Visa" , 3 = "platinum"

Now if a person suppose "john" has three credit cards then it will be stored as.

tblPersonCreditCard:
---------

CreditCardID PersonID CreditCardTypeID
1 1 1
2 1 2
3 1 3

Each if the number belong to one Field.

Which means that "john" has three credit cards

Now as u see that in tblPersonCreditCard john's id, which is 1 is repeating 3 time. how can I design a database in which the id does not repeat. I have heard that this can be done by using the bitwise operator but HOW.

thanks in advance,

AzamI don't see a problem with each record in tblPersonCreditCard including a foreign key to the credit card's owner. Is there some problem you're having with doing so?|||No i am not having any problem. But I just wanted to know that if there a better way of doing the same thing.|||There is no reason to do what you are attempting to do. To create a many-to-one relationship, you need to have a foreign key which will potentially repeat in the child table.|||I have heard that you can use some sort of the bit wise operator to store all the relationship of the person in a single field. I have no idea how ??|||I think you mean "bitmask", actually. Here'san article, if you're really interested.