Re: What is unique_id in Oracle and what's the use of it

On Jan 30, 8:47 am, newa <DavidLL...@xxxxxxxxx> wrote:
Hi,

I am new to Oracle and today someone asked me about the "fference
between unique_id and primary key. Which to use and why?" I know about
the primary key but not unique_id. Can someone kindly give me an
overview of it?

Thanks in advance.

Primary key is the combination of NOTNULL constraint and unique key
constraint.
so it ll never allow duplicate and null value.But unique key allows
number of null value but it never allow duplicate value.
Do not compare this to MS sqlserver, bcoz it some what different from
oracle to sql. Bcoz unique key will alow only one null value.

venki
.

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