Level Extreme platform
Subscription
Corporate profile
Products & Services
Support
Legal
Français
FK Constraint, Unique field constraint, Unique index
Message
 
 
To
All
General information
Forum:
Microsoft SQL Server
Category:
Other
Title:
FK Constraint, Unique field constraint, Unique index
Miscellaneous
Thread ID:
01639915
Message ID:
01639915
Views:
64
Hi,

I am changing the FK constraint from referencing just one column to two columns (was: CATEGORY, now SITE_NO, CATEGORY).

Before the change, I had to DROP UNIQUE FIELD CONSTRAIN on the parent table. Then I created a UNIQUE INDEX (not CONSTRAINT) and then created (on the parent table) the FK_CONSTRANT on the two columns (on the child table). All works.

What I don't understand is in which case I would need the UNIQUE FIELD CONSTRAINT (on the parent table)? I had it before, dropped it, created unique index and all works. I am just trying to see if I will miss something by not having the UNIQUE FIELD CONSTRAINT.

TIA
"The creative process is nothing but a series of crises." Isaac Bashevis Singer
"My experience is that as soon as people are old enough to know better, they don't know anything at all." Oscar Wilde
"If a nation values anything more than freedom, it will lose its freedom; and the irony of it is that if it is comfort or money that it values more, it will lose that too." W.Somerset Maugham
Next
Reply
Map
View

Click here to load this message in the networking platform