Difference between primary key and unique key ?
Answer Posted / suman chatterjee.
uniqe key may contain null values but primary key can not take the null values.
| Is This Answer Correct ? | 3 Yes | 3 No |
Post New Answer View All Answers
What do you understand by database schema and what does it hold?
What is a package ? What are the advantages of package ?
What are the oracle differences between nvl and coalesce
What are the attributes of the cursor?
how do we code triggers , store procedure , Performance tuning and indexing in a Java Project? Pls kindly get me the perfect answer with the code for each....thank you in advance............pls any body kindly help me soon as possible....
Explain what are the advantages of views?
What is the cache hit ratio, what impact does it have on performance of an Oracle database and what is involved in tuning it?
Explain an extent?
What is sharded cluster?
does the query needs a hint to access a materialized view?
What do you mean by a deadlock?
material view and view disadvantages?
What is a directory object?
Is there a combination of "like" and "in" in sql?
Whether any commands are used for months calculation? If so, what are they?