Foreign Keys

SQLServerCentral is supported by Red Gate Software Ltd.

Popular Topics

Home

Members

Calendar

Who's On

Home » Article Discussions » Article Discussions by Author » Discuss Content Posted by Ravi Lobo » Foreign Keys

19 posts, Page 2 of 2

««1 2

Foreign Keys

Rate Topic

Display Mode

Topic Options

Author

Message

Deepak Patil-309214

Posted Thursday, June 01, 2006 11:39 AM

Forum Newbie

Group: General Forum Members
Last Login: Tuesday, July 03, 2007 11:06 PM
Points: 3, Visits: 1

 If you don’t have a key, you don’t have a table!     
                  - Joe Celko

It is very nice article 
                which one can easly understand 
                without deep knowlege of MSSQL.

Also basic concepts are explained very well !!!!!

Post #284316

Roger Thomas

Posted Friday, June 02, 2006 1:04 PM

Forum Newbie

Group: General Forum Members
Last Login: Thursday, April 14, 2011 12:01 PM
Points: 6, Visits: 6

Good, terse explanation.

The only issue I'd have with it is the use of the terminology "Parent" and "Child" to describe the relationship between the primary key and the foreign key(s) that reference it. In the best methodologies I've seen, the terms "parent" and "child" are reserved for unusual situations where you have things that depend for their existence on other things. An example of this might be a line on an invoice - the invoice must exist for the line to exist, do the invoice would be the "parent" and the line the "child". With dissimilar things, such as drivers and racecars, you'd have two distinct entities that were related by a foreign key, but neither would be the "parent" of the other.

That's terminology, but it avoids confusion.

Post #284638

Ian Yates

Posted Saturday, June 03, 2006 12:40 AM

Ten Centuries

Group: General Forum Members
Last Login: Sunday, September 16, 2012 3:26 AM
Points: 1,038, Visits: 443

Fair comment from Roger. Makes me think actually that the next step for the article would be many-many relationship as many people get that confused

Post #284694

bitbucket-25253

Posted Wednesday, June 14, 2006 7:16 AM

SSCertifiable

Group: General Forum Members
Last Login: Today @ 4:33 AM
Points: 5,122, Visits: 20,365

As usual I am a day late and a dollar short, but heck was a good, clear, concise tutorial on foreign keys.

Thanks for the effort you put into this ... and as suggested by some one else, would be nice if you took the challenge and attempted to 'explain' the many to many relationship.

Again - thanks

If everything seems to be going well, you have obviously overlooked something.

Ron

Please help us, help you -before posting a question please read
Before posting a performance problem please read

Post #287330

Ravi Prashanth Lobo-275382

Posted Thursday, July 20, 2006 6:25 AM

Grasshopper

Group: General Forum Members
Last Login: Tuesday, March 20, 2007 12:30 PM
Points: 24, Visits: 1

Thank you all for your suggestions!

Post #295840

Vic Kirkpatrick-173212

Posted Thursday, May 31, 2007 5:48 AM

SSC-Addicted

Group: General Forum Members
Last Login: Thursday, November 13, 2008 9:13 AM
Points: 499, Visits: 76

To not use FKs in an OLTP with any level of complexity is just plain ignorant. There is no excuse for it, and you will just get badly burned. Amazingly enough, through my career I've had to fight developers, managers, and even other DBAs in order to install FKs on databases! It's incredible. In almost every case, they have grown to see the rewards by catching logic / data problems in testing with the FKs. Not to mention happy customers...

Post #370227

nogoodboyo

Posted Monday, June 11, 2007 10:24 PM

SSC Rookie

Group: General Forum Members
Last Login: Monday, January 09, 2012 3:37 AM
Points: 36, Visits: 352

No mention of trusted FK's? See http://sqlblog.com/blogs/hugo_kornelis/archive/2007/03/29/can-you-trust-your-constraints.aspx Handy to know, especially if you are lumbered with a db that exposes all data through very complex (and poorly performing )views!

Post #372950

balaji_rcs

Posted Thursday, November 01, 2007 3:02 AM

SSC Rookie

Group: General Forum Members
Last Login: Tuesday, July 27, 2010 9:23 AM
Points: 30, Visits: 93

Hi,

This is really a good article. I had an doubt about that i want to generate the insert statement script for moving the data from one db to another. Nearly 500 tables are there, i want to know how to prioritize the tables list. Becuase each and every tables are internally referenced. Can you please help out to fix the issue

Post #417428

naveenreddy.84

Posted Thursday, August 20, 2009 6:25 PM

Valued Member

Group: General Forum Members
Last Login: Wednesday, May 29, 2013 3:36 AM
Points: 54, Visits: 259

Hi,

Can you help me out in updating such Foreign Key relationships. In one of my tables, i have a FK relationship refering to my primary key of the same table.

The Table called MacMaster has following columns:

MacID MacName ClusterID

the ClusterID here is a foreign key referencing the MacID(PK) of the same table.

MacID(identity column;PK) MacName ClusterID
1 Mac1 2
2 Mac2 NULL

I was trying to load this table from an another table having following column

MacName ClusterName
Mac3 Mac4
Mac4 NULL
Mac5 NULL

Kindly suggest me a method to load the above data to MacMaster Table.
Finally my MacMaster table should have something like this:

MacID MacName ClusterID
1 Mac1 2
2 Mac2 NULL
3 Mac3 4
4 Mac4 NULL
5 Mac5 NULL

Is this can be achieved through TSql or do i need to create a some kind of front end for it.Kindly Suggest

Regards,

Post #774701

« Prev Topic | Next Topic »

19 posts, Page 2 of 2

««1 2

Permissions