Answer:
I think its option a. and d.
Explanation:
option a. is right I'm sure.
option b. and c. are doubtful for me.
option d. can be true. but unlike a job letter, resumes carry a deeper view of the employee's accomplishments and qualifications.
but I still hold with option a. and b. if it's wrong please do inform, so I can refer.
Explanation:
Both Primary Key and Candidate Key are the attributes that are used to access tuples from a table. These (Primary key and Candidate key) are also can be used to create a relationship between two tables.
- A Candidate Key can be any column or a combination of columns that can qualify as a unique key in the database. Each Candidate Key can qualify as a Primary Key.
- A Primary Key is a column or a combination of columns that uniquely identify a record. The primary key is a minimal super key, so there is one and only one primary key in any relationship.
<em> The main difference between them is that a primary key is unique but there can be many candidate keys. </em>
I hope you find this information useful and interesting! Good luck!
