what is difference between primary key and unique key
?
Answers were Sorted based on User's Feedback
Answer / chandonline
Basic difference between primary key and unique is that primary key is used to define a table in other tables for preventing data from anomalies,and unique key is used in a table to apply unifications among different values or columns of a tables and only in that table obviously.Their is no usage of unique key outward a table but primary key is often used to make relations between other tables.
| Is This Answer Correct ? | 3 Yes | 0 No |
Answer / ashish tyagi
The basic difference between primary key and unique key is that unique key allows null value but primary key did not allow null value.
| Is This Answer Correct ? | 2 Yes | 0 No |
State the acid rules?
How to use timestamp datatypes
What is a self join? Explain it with an example?
what is Normalization?
Which data type cannot be used as a parameter in a udf?
How can you fix a poorly performing query?
What are the types of database model?
explain detail about ftp in datastage?
I have a few records all are same structures data, I want to store data in multiple targets how
0 Answers CTR, Infosys, Polaris,
What are the three basic rules which are to be followed for the relational model of the database?
What is dbms and its application?
How can you log an error to the server event log from a stored procedure?
Oracle (3253)
SQL Server (4518)
MS Access (429)
MySQL (1402)
Postgre (483)
Sybase (267)
DB Architecture (141)
DB Administration (291)
DB Development (113)
SQL PLSQL (3330)
MongoDB (502)
IBM Informix (50)
Neo4j (82)
InfluxDB (0)
Apache CouchDB (44)
Firebird (5)
Database Management (1411)
Databases AllOther (288)