Interested to Buy Any Domain ? << Click Here >> for more details...
what is primary key,unique key, foreign key? can u teach me
in simple language?
- 44 Answers
- 189045 Views
- Banking, CMC, CTS, HCL, Infosys, Keggfarms, SkyEss, Sunrise, TCS, Web Synergies, Wipro, I also Faced
- E-Mail Answers
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
WHAT IS THE PURPOSE OF TESTING INTEGRITY OF THE UNIVERSE?
Give the syntax of exception handling used in DBMS?
How to do Stored procedure testing? Who does this testing (Developer or tester)?
What is sharded database?
what is rcp,if rcp disabled what happen?
What are the types of joins?
What will happen non-clustered index will be created on clustered index?
sparse lookup and where its options we find in OCI and db2?
What is the difference between data source and database?
What is lagging in DBMS ?
Which Statement would you use to remove the EMPLOYEE_Id_PK PRIMARY KEY constraint and all depending constraints from the EMPLOYEE table?
What does specialization in DBMS mean?
What is a database string?
How does non-cluster index functions?
Explain database partitioning. What is its importance?
