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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.

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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.


What is another name for a primary key?

Also called a Key field.


True or false A foreign key is a field in one table that refers to the primary key field in another table and indicates how the the tables are related?

True.


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


Primary and secondary key in DBMS?

key is nothing but a attribute and attribute is the aspect of a member in an entity entity is represented by set of attributes. primary key is the one which is selected by the database designer to identify a entity in a entity set super key is one or more attributes which is used to identify the entity in an entity set uniquely candidate key minimal number of super keys... in some context super key and secondary key are equal. foreign key is the relational constraint between tables or entities A secondary key is made on a field that you would like to be indexed for faster searches! For any Further detail,you visit this website:http://www.iyogibusiness.com

Related Questions

Which field MS Access will not allow you to delete?

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.


What are field can be used as primary key?

A field or set a of fields Êin a database tableÊwith unique values Êcan be used as a primary key.ÊPrimary key field cannot have a null value.


What is A field that uniquely identifies a particular record in a table called?

A field that uniquely identifies a particular record in a table is called a primary key. The field or fields on which records are sorted is called the sort key.


What not a likely primary key?

A field that is not unique and null can not be used as a primary key. Praimary key must satisfy the conditions of not null and unique.


What is the difference between a Primary Key and a Secondary Key?

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.


In a data base the primary key field is used to?

uniquely identify a record


What is the meaning of primary key in Microsoft access?

The primary key is the designation given to the field or fields that make a record unique in a table. Often times in Access an autonumber field is used as the primary key because Access will always generate a unique number for each record. Having a primary key is not a requirement but it is highly recommended that you have a primary key in each table.


Is the last name a primary key?

A primary key is always unique and not null. It is prefer to choose a field that is unique like roll number . But to choose Last name as a primary key is not a good option as two people can have same last name.A Last name field is not a good one for a primary key. A primary key cannot have duplicate values. A last name field is highly likely to have duplicate values, so it should not be used as a primary key.


What is candidate key in dbms?

more than one primary key to identify the record uniquely is called candidate key.


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.


Differentiate between primary secondary and foreign keys?

Primary key uniquely identifies each record in a database table and must have a unique value for each record. Secondary key is a field that can be used to uniquely identify a record, but it is not the primary key. Foreign key is a field in a table that links to the primary key of another table, establishing a relationship between the two tables.


Can the FirstName column be a primary key?

A First name field is not a good one for a primary key. A primary key cannot have duplicate values. A first name field is highly likely to have duplicate values, so it should not be used as a primary key.