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The foreign key is used as a reference in a table to the primary key of another table. For example: consider a table employee with id(primary key), name, address,department_id(foreign key) as its fields.Another table department with fields department_id(primary key) and dept_name.
So, department_id is primary key in department table and foreign key in employee table.
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∙ 9y ago
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.
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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.
What is the condition for a key to be a foreign key?
A key is considered a foreign key if it references the primary key of another table to establish a relationship between the two tables. It enforces referential integrity, ensuring that data in the foreign key column corresponds to data in the primary key column.
What is the function of a Foreign Key in SQL?
A Foreign Key in SQL is used to establish a relationship between two tables. It ensures referential integrity by enforcing that values in a column (or columns) in one table must match the values in a primary key in another table. This helps maintain consistency and data integrity across linked tables.
How can a Foreign Key and a Primary Key interact with each other?
A foreign key in a table references the primary key in another table, creating a relationship between the two tables. This ensures referential integrity, meaning that values in the foreign key column must exist in the primary key column. This relationship allows data to be linked and maintained consistently between the tables.
When checking the database you confirm that the Enforce Foreign Key Constraint property is set to Yes as expected. What property does this constraint create for the database?
The Foreign Key Constraint property creates a relationship between two tables in the database. It enforces referential integrity, ensuring that a foreign key column in one table must have a corresponding primary key value in another table. This helps maintain data consistency and avoid orphaned records.
What is the key term aid mean?
Foreign Aid is when, after a disaster etc.., a foreign country gets involved in humanitarian issues to help the foreign country (ex. The United States helping Haiti after the earthquake.)
Types of keys in database management system?
super key foreign key candidate key surrogate key unique key alternate key composite key compound key
What is the foreigh key in DBMS explainwith example?
In the context of relational databases, a foreign key is a referential constraint between two tables.[1] The foreign key identifies a column or a set of columns in one (referencing) table that refers to a column or set of columns in another (referenced) table. The columns in the referencing table must be the primary key or other candidate key in the referenced table. A table may have multiple foreign keys, and each foreign key can have a different referenced table. Each foreign key is enforced independently by the database system. Therefore, cascading relationships between tables can be established using foreign keys. Improper foreign key/primary key relationships or not enforcing those relationships are often the source of many database and data modeling problems.
What is the purpose of cascade delete and cascade update?
When a database has a foreign key "cascade" operations mean operations on the _parent_ will cascade (impact) the _child_ (foreign key reference)
The key foreign policymakers are?
The key foreign policy makers are?
Can a foreign key be null?
yes .a foreign key can have null values
What is the term that would mean the present is the key to the past?
Uniformatarianism.
What is the meaning for primary key in database?
With reference to Databases, what are Primary keys?
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.
How do you use foreign key in to oracle?
the foreign key referential between two tables.
What key defines a relationship between two tables 1 Primary key 2 Secondary key 3 Foreign key?
Foreign key is used to define a relationship between two tables by referencing the primary key of another table. It ensures data integrity and enforces referential integrity between the related tables.
Can a foreign-key column can contain duplicate values?
yep foreign key can have duplicate values
