Difference between primary key and unique key ?
Answer Posted / praveen
primary key not allows null values, but unique key allows null values. only one primary is possible in one table, but multiple unique keys are possible in a table. Each unique key accepts only one null field. Both are used to prevent repeated entry of values.
| Is This Answer Correct ? | 1 Yes | 1 No |
Post New Answer View All Answers
How to define a specific record type?
How to check the oracle tns settings?
does the query needs a hint to access a materialized view?
What is a table in oracle?
What do you understand by database schema and what does it hold?
How to view the tablespaces in the current database?
What is the database name in oracle?
What is an oracle function?
How to convert character types to numeric types?
What is a table index in oracle?
What is the quickest way to export a table to a flat file?
Is oracle a programming language?
How can we find out the duplicate values in an oracle table?
src name sex a,male b,female c,male d,female Required output : male female a,b c,d tried pivot but was not successfull select * from src pivot (max(name) for sex in ('MALE','FEMALE'));
what is the need of indexing topic in oracle? where do we use in a Java project? any other option other than using this to get the same result where we use indexing ?