It is easy
In sql you use primary key more than one column in a table
A primary key field.A primary key field.A primary key field.A primary key field.A primary key field.A primary key field.A primary key field.A primary key field.A primary key field.A primary key field.A primary key field.
without you will not be able to create a relationship
I think super key is treated as the primary key because in a table their will be only one primary key.
removing the primary key is very simple, all you need to do is click on that specif field and at the top of the page there will be a key sign. once the field is highlightes then just click the key tab and it should be then removed
Importance of primary key
We know that primary key is the one that is not null and is always unique. A primary key uniquely identifies a record in a table.
Primary key that is used to identify a record uniquely. Primary key is a key that always unique and not null. A system generated primary key is called surrogate key.Primary key is the one which is always unique and not null. Advantage of primary key that it helps in identifying a tuple uniquely.
Primary key is to set property ID as the primary key for the properties table.
A primary key is never null and is also unique . Example of primary key is create table emp (ecode integer NOT NULL PRIMARY KEY);
We designate one of the candidate key of a relation to be a primary key because that primary key is use for any foreign key references.
A Primary Key is a unique identifier for each record in a database table and is used to enforce entity integrity. A Secondary Key is a non-unique index that is used for querying and organizing data efficiently but does not have the constraint of uniqueness.