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what is primary key and foreign key when and where have to use
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Answer / prashant
primary key has a unique & it is only one in a
databasewhile fkey is not unique. it is based on primary key
| Is This Answer Correct ? | 2 Yes | 0 No |
Answer / ramprasad.s
HI
Primary key = (Not Null + Unique).
Foreign key = (For Referential table access).
Bye
sun_ramprasad@yahoo.com
| Is This Answer Correct ? | 2 Yes | 1 No |
Answer / chandrika
primary key has unique value, it dostnt contain null values
and duplicate values.
foregin key is primary key of another table
| Is This Answer Correct ? | 2 Yes | 2 No |
Answer / raveendran
Primary key is unique across entire table.In primary key
not null constraint is activated.Only one primary key in
one table.
foreign key points to primary key of another table
| Is This Answer Correct ? | 0 Yes | 0 No |
Answer / csprusty
To establish a relationship between 2 tables.
pk=(unique+not null)
fk=unique
| Is This Answer Correct ? | 1 Yes | 2 No |
consider some table with 4 r 5 columns in that 1 col is DATE type. The data is like that,For each date in that col some 3 fields r there but all the records r having different data. Now i want to display all the columns by performing grouping on the date field ( as SELECTION Operator(*) cannot be used with group function having only one "group by clause". how to do this? can any one help me in finding out the solution plss?
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