Обсуждение: E-R diagram code U1
Looking at the entity-relationship diagram for a regulatory agency database they have attribute identifiers of PK, FKn, and U1. The first is the Primary Key and the second is a Foreign Key, but I've not before seen a 'Un' identifyier. I've no idea what DBMS they're using (but suspect Oracle). My web search used in-effective terms so I could not find the answer there. What does U1 represent? Rich
Rich Shepard <rshepard@appl-ecosys.com> writes:
> Looking at the entity-relationship diagram for a regulatory agency database
> they have attribute identifiers of PK, FKn, and U1. The first is the Primary
> Key and the second is a Foreign Key, but I've not before seen a 'Un'
> identifyier. I've no idea what DBMS they're using (but suspect Oracle). My
> web search used in-effective terms so I could not find the answer there.
> What does U1 represent?
Unique constraint, perhaps? I'm just guessing.
regards, tom lane
On Sat, 29 Oct 2016, Tom Lane wrote: >> What does U1 represent? > > Unique constraint, perhaps? I'm just guessing. Tom, That's my guess, too. I've not seen it used before now and did not know if it's a standard code for something or one specific to this agency. Thanks, Rich
On 10/29/2016 09:47 AM, Rich Shepard wrote: > On Sat, 29 Oct 2016, Tom Lane wrote: > >>> What does U1 represent? >> >> Unique constraint, perhaps? I'm just guessing. > > Tom, > > That's my guess, too. I've not seen it used before now and did not > know if > it's a standard code for something or one specific to this agency. http://stackoverflow.com/questions/5628533/what-does-i1-i2-u1-means-in-visio-database-relationship-diagram http://stackoverflow.com/questions/23533702/about-entity-relationship-diagram > > Thanks, > > Rich > > -- Adrian Klaver adrian.klaver@aklaver.com
On Sat, 29 Oct 2016, Adrian Klaver wrote: > http://stackoverflow.com/questions/5628533/what-does-i1-i2-u1-means-in-visio-database-relationship-diagram > http://stackoverflow.com/questions/23533702/about-entity-relationship-diagram Thanks, Adrian. I suspected that I was not effectively expressing my search terms. Rich