What is the advantage of Foreign Key in Oracle?

[addisoncave]

Hi guys, I want to know what is the advantage of foreign key in Oracle while we don't use the same thing with Mysql. do this make any difference?

[jackar56]

Foreign keys are both a method of ensuring data integrity and a manifestation of the relationship between tables. It is also known as referential integrity.Foreign Key is a field in database table that is Primary key in another table. It can accept multiple null, duplicate values. We can have more than one foreign key in a table.Foreign key do not automatically create an index, clustered or non-clustered. You can manually create an index on foreign key.

[jameswarner1]

Foreign key provides referencing another table using the primary key for the other table.

[jackar56]

A foreign key is a column or group of columns in a relational database table that provides a link between data in two tables.

[jacks]

Oracle Database can enforce the relationship between the two tables through a foreign key constraint, also called a referential integrity constraint.The value of foreign keys can match either the referenced primary or unique key value, or be null.

[ziya.pathan]

Foreign Keys are necessary for maintaining integrity and consistency of your data in a corporate production environment. The cost is they can considerably slow down Inserts if you do not have indexes on the key in the parent table. This is especially the case where you may have a single fact like table, with multiple FK’s. Upon Insert, the database will do a lookup and if no index is present, your transactions can take longer to validate. I know the last time I focused on an ORM like Entity Framework it did not generate FK’s by default.