Database - Data Models into Database Designs - Discussion
Discussion Forum : Data Models into Database Designs - General Questions (Q.No. 4)
4.
A primary key should be defined as:
Discussion:
4 comments Page 1 of 1.
Dipali said:
7 years ago
Obviously. We don't need to define as not null because whenever it is set the column becomes automatically not null.
Mateti shiva said:
8 years ago
Primary is always not null then why should we define again it as not null. Answer is none of the above.
DilipM19 said:
9 years ago
Primary key is an identifier or field which uniquely defined a record in entity(generally table).
Anu said:
1 decade ago
Primary key means it is not null and duplicate values are not allowed.
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