what is primary key,unique key, foreign key? can u teach me
in simple language?
Answer Posted / navya
pk-it doesn't accept null values.there must be only one pk in table.
unique-it accept null values.there may be one r more unique keys in a table.
foreign-used to refer any key
| Is This Answer Correct ? | 0 Yes | 0 No |
Post New Answer View All Answers
Why merge statement is used inside the database?
how can we view column head in first page but not in remaining pages?
Is hive a database?
There are three servers are run by Oracle, MS Access and .Net. What are the procedure fetching the values of two variables from two servers among these?
What is database bounce?
How to shrink a database?
What is ole db source in ssis?
What are the tools used for backup and ticketing?
can any one tell me how i can start database testing mean what should be initial point and how i can write a query for listing page of any item thanks in advance
Which Statement would you use to remove the EMPLOYEE_Id_PK PRIMARY KEY constraint and all depending constraints from the EMPLOYEE table?
What are database connection details?
HOW WE PASS PARM PARAMETERS TO CL VARIABLES FROM RPGLE?
can i use the commands "modify" and Change in DB2 to alter my column datatype and its name in a table?
Explain buffer manager?
Explain database partitioning.