Solved

MS SQL Server 2008 Data integrity FK NULL

Posted on 2008-11-02
21
445 Views
Last Modified: 2013-12-07
I'm going to be real lame here and ask an easy question.. I think.. this is to make
up for later when I ask a reeeeaaalllllly hard question and get really fussy.  Be warned!

You see I have successfully created a couple of tables.  "Table _1 " is now called
"Sales_Rep" as I have saved it thus refreshing the name on the tab.  I need
"seller" to be a foreign key referring to the primary key "name" of Sales_Rep but
I think it is okay if it is null?  hmm.. yes.  I think an unsold Automobile (Table_2) can
be in the database.

Maybe I have to click that relationship jobbie?
seller.jpg
0
Comment
Question by:kayvey
  • 18
  • 3
21 Comments
 
LVL 17

Accepted Solution

by:
HoggZilla earned 500 total points
ID: 22864266
Question: Can a FK be NULL
Answer: Yes: A FOREIGN KEY constraint does not have to be linked only to a PRIMARY KEY constraint in another table; it can also be defined to reference the columns of a UNIQUE constraint in another table. A FOREIGN KEY constraint can contain null values; however, if any column of a composite FOREIGN KEY constraint contains null values, verification of all values that make up the FOREIGN KEY constraint is skipped. To make sure that all values of a composite FOREIGN KEY constraint are verified, specify NOT NULL on all the participating columns.
Question: How do I define a FK relationship in SQL
Answer: Several Options: http://msdn.microsoft.com/en-us/library/ms177463.aspx
 
0
 

Author Comment

by:kayvey
ID: 22864299
I'm in touchy feely Windoze moode.  I dont know where to type the SQL right now.  Can I right click on something instead?
0
 

Author Comment

by:kayvey
ID: 22864374
I press buttons dwive me kwayzey
FK-wazyzey.jpg
0
Optimizing Cloud Backup for Low Bandwidth

With cloud storage prices going down a growing number of SMBs start to use it for backup storage. Unfortunately, business data volume rarely fits the average Internet speed. This article provides an overview of main Internet speed challenges and reveals backup best practices.

 

Author Comment

by:kayvey
ID: 22864378
I'm not trying to make this hard.  I think we are close this one.
0
 

Author Comment

by:kayvey
ID: 22864399
That's better. I saved with right names now. Automobile.seller must be Sales_Rep.name.  seller FK to
Sales_RepPK.name.  
sellerFKname.jpg
0
 

Author Comment

by:kayvey
ID: 22864412
Now you see Sales_Rep.  Sales_Rep (s) he have name(S)
namePK.jpg
0
 

Author Comment

by:kayvey
ID: 22864445
oh oh., bad danger. soooo many windoze i never asked for
badPKdanger.jpg
0
 

Author Comment

by:kayvey
ID: 22864536
Okay I done now with kwayzey nonsense?  i have no idea.
PKFKdone.jpg
0
 

Author Comment

by:kayvey
ID: 22864548
Can you read that? It is Foreign Key Relationships Diagalog woohaw.

-Tables and Columns Specifica
       Foreign Key Base Table         Automobile
       Foreign Key Columns             seller
       Primary/Unique Key Base Ta Sales_Rep
       Primary/Unique Key Column  name
-Identity
   (Name)                                       FK_Automobile_Sales_Rep
   
0
 

Author Comment

by:kayvey
ID: 22864594
this is kwayzey awful slow
0
 

Author Comment

by:kayvey
ID: 22864597
I mean my stooopid awful old puter running Vista.. I save I save It confused.
0
 

Author Comment

by:kayvey
ID: 22864658
Tables and Columns make me mad.  Can't change Forieng key table.

oopsie!   got it backards?
ornery.jpg
combobulate.jpg
0
 

Author Comment

by:kayvey
ID: 22864710
oooh nooo!!! bad saving.. agnrgy windowze..won't let me save now.. make
stupid system32 textfile
saveProb.jpg
systemTxt.jpg
0
 

Author Comment

by:kayvey
ID: 22864728
nooooo!  not stupid cancle!! this disaster bad wrong bad wrong wrong bad bad bad rowong
worong wong wong wrong wrong
cancel.jpg
0
 

Author Comment

by:kayvey
ID: 22864800
THIS LAST STRAW DISASTER NONSENSE>  HOW TO DROP DANG TABLES??
exErr.jpg
0
 
LVL 17

Expert Comment

by:HoggZilla
ID: 22866069
You are hilarious. I have no idea where you are now, sorry. What can I do to help. I thought you had it there but it seems you and your database are not on good terms?
0
 

Author Comment

by:kayvey
ID: 22868280
Did I do the FK right?
0
 

Author Comment

by:kayvey
ID: 22868477
Okay I guess it's fine.  Now how do I populate the tables?
0
 

Author Comment

by:kayvey
ID: 22868526
I got this stupid thing called Power Shell.. maybe that's where I type SQL? I don't want to lookup nonsense.Where is stupid spreadsheet type view of data in fields?
powerShell.jpg
0
 
LVL 17

Assisted Solution

by:HoggZilla
HoggZilla earned 500 total points
ID: 22869235
In SQL Server management Studio, behind your above console screen, Right Click on the table and select Open Table. There you can type values into the columns directly.
0
 

Author Comment

by:kayvey
ID: 22870087
It's not Open table.  It's Edit top 200 lines..

allrighty then.  I guess that'll do it.  Thank you, sir.
0

Featured Post

Best Practices: Disaster Recovery Testing

Besides backup, any IT division should have a disaster recovery plan. You will find a few tips below relating to the development of such a plan and to what issues one should pay special attention in the course of backup planning.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

In this article we will get to know that how can we recover deleted data if it happens accidently. We really can recover deleted rows if we know the time when data is deleted by using the transaction log.
This article shows gives you an overview on SQL Server 2016 row level security. You will also get to know the usages of row-level-security and how it works
Via a live example, show how to restore a database from backup after a simulated disk failure using RMAN.
Viewers will learn how the fundamental information of how to create a table.

832 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question