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MS SQL Server 2008 Data integrity FK NULL

Posted on 2008-11-02
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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
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Question by:kayvey
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LVL 17

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HoggZilla earned 500 total points
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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
 
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by:kayvey
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I'm in touchy feely Windoze moode.  I dont know where to type the SQL right now.  Can I right click on something instead?
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Author Comment

by:kayvey
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I press buttons dwive me kwayzey
FK-wazyzey.jpg
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Author Comment

by:kayvey
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I'm not trying to make this hard.  I think we are close this one.
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Author Comment

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

by:kayvey
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Now you see Sales_Rep.  Sales_Rep (s) he have name(S)
namePK.jpg
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Author Comment

by:kayvey
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oh oh., bad danger. soooo many windoze i never asked for
badPKdanger.jpg
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Author Comment

by:kayvey
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Okay I done now with kwayzey nonsense?  i have no idea.
PKFKdone.jpg
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Author Comment

by:kayvey
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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
   
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by:kayvey
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this is kwayzey awful slow
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Author Comment

by:kayvey
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I mean my stooopid awful old puter running Vista.. I save I save It confused.
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Author Comment

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

oopsie!   got it backards?
ornery.jpg
combobulate.jpg
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Author Comment

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

by:kayvey
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nooooo!  not stupid cancle!! this disaster bad wrong bad wrong wrong bad bad bad rowong
worong wong wong wrong wrong
cancel.jpg
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Author Comment

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

Expert Comment

by:HoggZilla
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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?
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Author Comment

by:kayvey
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Did I do the FK right?
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Author Comment

by:kayvey
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Okay I guess it's fine.  Now how do I populate the tables?
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Author Comment

by:kayvey
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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
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LVL 17

Assisted Solution

by:HoggZilla
HoggZilla earned 500 total points
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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.
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Author Comment

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

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