what is primary key,unique key, foreign key? can u teach me
in simple language?
Answer Posted / kranthi
primary key: primary creates a clustered index on the
column and it doesn't allow null values.
unique key: unique key creates non clustered index by
default.it allows "one null value".
foreign key: A foreign key (FK) is a column or combination
of columns used to establish and enforce a link between the
data in two tables
Is This Answer Correct ? | 212 Yes | 76 No |
Post New Answer View All Answers
Difference between sql and mysql?
Should I store images in database?
Explain transaction manager?
How do you pass parameter in stored procedure?
When should you not use firebase?
How to do Stored procedure testing? Who does this testing (Developer or tester)?
What is the role of driver manager?
Why do we need distributed database?
What is a trace file?
What is the database url?
What are the most common databases?
Why merge statement is used inside the database?
What is Object Oriented model?
What is database server and how it works?
What does new grouping sets enables you to do?