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Is it necessarily that a foreign key is primary key in other table?
Wiki User
∙ 14y ago
It is not mandatory that is must be a primary key but it must be a unique key in the other table.
Wiki User
∙ 14y ago
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How functional dependency is related to database table design?
The functional dependency is related to the database table design through the foreign and primary keys. The foreign and primary keys are functionally dependent on each other.
Why must the primary key of a parent table be determined before the foreign key in the child table?
Because the foreign key is copied from the primary key of the parent table
Can a primary key be a foreign key?
Yes, a primary key can also be a foreign key. This is known as a composite key, where one or more columns in a table are both primary keys for that table and also act as foreign keys linking to another table.
Could a table only have one primary key and only one foreign key?
Yes it could. It would have a primary key for its own use and it could then have a foreign linking it to another table. If it is only linked to one other table, then it would only need one foreign key. It is also possible to have the same foreign key linking to more than one table.
What does the term foreign key mean in databases?
A foreign key is a field in a database table that is used to establish a relationship with another table. It ensures referential integrity by enforcing a link between two tables based on a matching key. This key is typically a primary key in the referenced table.
The foreign key uniquely identifies a record in a table T or F?
False. A foreign key is a primary of one table that is in another table. A foreign key can be repeated, so it does not uniquely identify records in the table where it is a foreign key.
foreign key?
when a primary key from one table is stored as an attribute of another table
What is Relationship between a primary and a foreign key?
A primary key is one or more colums in a table whose values would uniquely identify a row in that table. A foreign key is a one or more columns in one table that are used to reference rows in another table. In a properly designed 3NF schema, the foreign key columns should correspond to the primary key columns of the table being referenced.
Is a foreign key field always on the one side of a one-to-many relationship between two tables?
No. The foreign key is always on the many side. A foreign key is a field that is a primary key in another table, not in the table it is in. It can therefore be repeated in the table it is, so it can act as the many side. In its own table, it is the primary key, and only appears once.
What is the difference between a primary key and a foreign key?
A primary key uniquely identifies each record in a table and ensures data integrity. A foreign key establishes a relationship between two tables, referencing the primary key of another table to enforce referential integrity.
Why you need primary key and foreign key?
In sql you use primary key more than one column in a table
What Is the primary key of another table that is included for purposes of establishing relationships?
Foreign Key
