Diff between Composite key, Alternate Key, Candidate Key,
Primary Key, Unique Key, Super Key, Foreign Key
Answer / sapan saxena
Super Key: All possible keys which can identify entities in
the table uniquely.
Primary Key: uniquely identify each entity in the table and
does not contain null and duplicate vales.
Composite key: The combination of two or more than two keys
which identifies entities uniquely.
Candidate Key: Nominee for the primary key.
Alternate Key: Rest of the candidate keys which is not the
primary key.
Unique Key: Same as primary key but can accept one null key
only.
Foreign Key: A foreign key is one or more columns whose
value must exist in the primary key of another table.
Is This Answer Correct ? | 41 Yes | 2 No |
How will you find out if there are expensive SQL statements running or not?
How many nested transaction can possible in sql server?
What is the difference between function and stored procedure in sql server?
What is entity data services?
What is global temp table?
Explain the properties of the relational tables?
What is the difference between WHERE AND IN? OR 1. SELECT * FROM EMPLOYEE WHERE EMPID=123 2. SELECT * FROM EMPLOYEE WHERE EMPID IN (123) WHAT IS THE DIFFERENCE?
What is the optimal disk configuration for a database server and what raid configurations would you use if budget is not a constraint?
What are system databases into sql server (2005/2008)?
What is hot add cpu in sql server 2008?
Explain difference between cross join and full outer join?
Explain time data type in sal server 2008?