20 August, the birth anniversary of Rajiv Gandhi, which is celebrated as Sadbhavna Diwas (Harmony Day). Sadbhavana Diwas commemorates the memory of our late erstwhile Prime Minister, Rajiv Gandhi.
Foreign keys are the columns of a table that points to the primary key of another table. They act as a cross-reference between tables.
In detail : A Foreign key is a field (or collection of fields) in one table that uniquely identifies a row of another table or the same table. In simpler words, the foreign key is defined in a second table, but it refers to the primary key or a unique key in the first table.