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What is another name for a primary key?

Also called a Key field.


what field is used as a primary key?

We explicitly choose a primary key.A primary key should satisfy the following conditions: 1) it should not be null 2) it should be unique.


Can you insert primary key only to one field in the database?

Yes. Primary key can be inserted to one field in the database. The field should be unique and not null.


Difference between primary key candidate key and super key?

A primary Key which uniquely identifies a row of table,primary key does not allow null values and also not allow duplicate values. Superkey is defined in the relational model of database organization as a set of attributes of a relation variable (relvar) for which it holds that in all relations assigned to that variable there are no two distinct tuples (rows) that have the same values for the attributes in this set. Equivalently a superkey can also be defined as a set of attributes of a relvar upon which all attributes of the relvar are functionally dependent. If you more information so you can visit this website:http://www.iyogibusiness.com


All types of keys in database?

* Alternate key - An alternate key is any candidate key which is not selected to be the primary key * Candidate key - A candidate key is a field or combination of fields that can act as a primary key field for that table to uniquely identify each record in that table. * Compound key - compound key (also called a composite key or concatenated key) is a key that consists of 2 or more attributes. * Primary key - a primary key is a value that can be used to identify a unique row in a table. Attributes are associated with it. Examples of primary keys are Social Security numbers (associated to a specific person) or ISBNs (associated to a specific book). In the relational model of data, a primary key is a candidate key chosen as the main method of uniquely identifying a tuple in a relation. * Superkey - A superkey is defined in the relational model as a set of attributes of a relation variable (relvar) for which it holds that in all relations assigned to that variable there are no two distinct tuples (rows) that have the same values for the attributes in this set. Equivalently a superkey can also be defined as a set of attributes of a relvar upon which all attributes of the relvar are functionally dependent. * Foreign key - a foreign key (FK) is a field or group of fields in a database record that points to a key field or group of fields forming a key of another database record in some (usually different) table. Usually a foreign key in one table refers to the primary key (PK) of another table. This way references can be made to link information together and it is an essential part of database normalization

Related Questions

Is Karnataka high school teacher recruitment exam key answers 2009?

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Which field MS Access will not allow you to delete?

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What are the key considerations for parents when choosing an international primary school for their child?

When choosing an international primary school for their child, parents should consider factors such as the school's curriculum and educational approach, language options, teacher qualifications and experience, class size and student-teacher ratio, facilities and resources, extracurricular activities, support services for diverse learning needs, community and parent involvement, location and transportation options, and overall reputation and accreditation.


Is Karnataka high school teacher recruitment exam key answers 2012?

yes


Where can you find the 2009 NYS ELA test answer key?

You should ask your teacher or just wait for the results.


Can super key be as primary key?

I think super key is treated as the primary key because in a table their will be only one primary key.


What are the importance of primary key?

Importance of primary key


What does the primary key in a data base do?

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.


What are the advantage of primary key?

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.


What is the primary key for the properties table?

Primary key is to set property ID as the primary key for the properties table.


How you create or assign primary key?

A primary key is never null and is also unique . Example of primary key is create table emp (ecode integer NOT NULL PRIMARY KEY);


Why do you designate one of the candidate key of relation to be the 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.