primary key is the unique constraint on the table,which identify each tuple uniquely where as secondary key is also constaint on table but it can identify more than one reconds in table...
A primary key is a unique identifier for a record in a database table and is used to ensure each record is uniquely identifiable. A secondary key is a key used for sorting and indexing purposes, but can have duplicate values within a table.
A primary key uniquely identifies each record in a table and ensures data integrity. A foreign key establishes a relationship between two tables, referencing the primary key of another table to enforce referential integrity.
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.
A primary key is an attribute (or combination of attributes) that uniquely identifies each row in a relation. A primary key is designated by underlining the attribute name. The primary key of an entity set allows us to distinguish among the various entities of the set. A foreign key is an attribute in a relation of database that serves as the primary key of another relation in the same database.
A primary key is a unique identifier for each record in a database table and is used to ensure data integrity and enforce entity integrity. A secondary key, also known as a candidate key, is an alternate unique key that can be used to identify records, but is not designated as the primary key.
Super key: A set of attributes that uniquely identifies a tuple in a table. Primary key: A specific super key chosen to uniquely identify each tuple in a table and must be unique and not null. Candidate key: Any super key that could be chosen as the primary key. Foreign key: A field in a table that is a primary key in another table, used to establish a relationship between the two tables.
There is two difference between them. 1. The not null constraint is by default added to primary key, it means, primary key attribute cannot accept null values, whereas, the attribute declared as unique can accept null values. It is the major difference between the two. 2. Secondly, we can have only one primary key in a relation, whereas, multiple attributes can be declared unique at the same time.
A primary key uniquely identifies each record in a table and ensures data integrity. A foreign key establishes a relationship between two tables, referencing the primary key of another table to enforce referential integrity.
Candidate Key is used to uniquely identify the records of a table. An attribute becomes a Primary Key, if all the other candidate keys lose race for being qualified as Primary Key.
Primary key is a type of unique index with no null constraint on the columns involved. There can only be one Primary key whereas you can create other unique indexes on the table.
There are two types of keys in any database; composite and primary keys. Composite key differs from primary key in that it contains more than one column while primary key is composed of only one field and cannot have a null value.
establishing a relation between two tables called fornkey.......the colum name should be unique is called "primary key"...a table contain only one primary key...a table contain more then one fornkey....
A primary key is a unique identifier for a record in a table and ensures each record is uniquely identified. A foreign key establishes a relationship between two tables by referencing the primary key in another table. It enforces referential integrity by ensuring that the values in the foreign key column correspond to values in the primary key column of another table.
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.
don't ask me I'm trying to find out to but i think it has something to do with the government
A primary key is an attribute (or combination of attributes) that uniquely identifies each row in a relation. A primary key is designated by underlining the attribute name. The primary key of an entity set allows us to distinguish among the various entities of the set. A foreign key is an attribute in a relation of database that serves as the primary key of another relation in the same database.
A primary key is a unique identifier for each record in a database table and is used to ensure data integrity and enforce entity integrity. A secondary key, also known as a candidate key, is an alternate unique key that can be used to identify records, but is not designated as the primary key.
The difference is that partial dependency is when a database's attribute is only partially dependent on the primary key. Fully functional dependency is when the attribute is entirely dependent on the key.