What Is Primary Key?
A Primary key frequently emphasises the table’s oneness. Every row in the database is uniquely linked by a column or group of columns. It shouldn’t contain any duplicate values, according to this. also, it does not have a NULL value.
What Is Foreign Key?
Typically, a foreign key is utilised to establish a connection between the two tables. To maintain data integrity between two different instances of an object, the foreign key’s primary function is to be
| SR.No | Primary Key | Foreign Key |
| 1 | A Primary key often emphasises the table’s uniqueness. It guarantees that the value in that particular column is distinct. | Typically, a foreign key is utilised to establish a connection between the two tables. |
| 2 | Table allows only one primary key. | Tables support multiple foreign keys. |
| 3 | The primary key doesn’t allow null values. | Foreign key accepts multiple null values. |
| 4 | It is capable of uniquely identifying the record in the database table. | A field in a table that serves as the main key in another table is known as a foreign key. |
| 5 | The value in the primary key cannot be deleted from the parent table. | This allows for the deletion of the value from the child table. |
| 6 | The temporary tables can be used to specify its restriction totally. | It is not possible to define its restriction on either the global or local temporary tables. |
