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Primary key

Index Primary key

In the relational model of databases, a primary key is a specific choice of a minimal set of attributes (columns) that uniquely specify a tuple (row) in a relation (table). [1]

18 relations: Active record pattern, Candidate key, Column (database), Database, Due diligence, National identification number, Natural key, Object-relational mapping, Relation (database), Relational database management system, Relational model, Row (database), SQL, SQL:2003, Superkey, Surrogate key, Table (database), Unique key.

Active record pattern

In software engineering, the active record pattern is an architectural pattern found in software that stores in-memory object data in relational databases.

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Candidate key

In the relational model of databases, a candidate key of a relation is a minimal superkey for that relation; that is, a set of attributes such that.

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Column (database)

In a relational database, a column is a set of data values of a particular simple type, one value for each row of the database.

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A database is an organized collection of data, stored and accessed electronically.

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Due diligence

Due diligence is an investigation of a business or person prior to signing a contract, or an act with a certain standard of care.

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National identification number

A national identification number, national identity number, or national insurance number is used by the governments of many countries as a means of tracking their citizens, permanent residents, and temporary residents for the purposes of work, taxation, government benefits, health care, and other governmentally-related functions.

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Natural key

A natural key (also known as business key) is a type of unique key, found in relational model database design, that is formed of attributes that already exist in the real world.

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Object-relational mapping

Object-relational mapping (ORM, O/RM, and O/R mapping tool) in computer science is a programming technique for converting data between incompatible type systems using object-oriented programming languages.

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Relation (database)

In relational database theory, a relation, as originally defined by E. F. Codd, is a set of tuples (d1, d2,..., dn), where each element dj is a member of Dj, a data domain.

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Relational database management system

A relational database management system (RDBMS) is a database management system (DBMS) based on the relational model invented by Edgar F. Codd at IBM's San Jose Research Laboratory.

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Relational model

The relational model (RM) for database management is an approach to managing data using a structure and language consistent with first-order predicate logic, first described in 1969 by Edgar F. Codd, where all data is represented in terms of tuples, grouped into relations.

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Row (database)

In the context of a relational database, a row—also called a tuple—represents a single, implicitly structured data item in a table.

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SQL (S-Q-L, "sequel"; Structured Query Language) is a domain-specific language used in programming and designed for managing data held in a relational database management system (RDBMS), or for stream processing in a relational data stream management system (RDSMS).

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SQL:2003 is the fourth revision of the SQL database query language.

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A superkey or super-key is defined in the relational model of database organization as a set of attributes of a relation variable 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.

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Surrogate key

A surrogate key (or synthetic key, entity identifier, system-generated key, database sequence number, factless key, technical key, or arbitrary unique identifier) in a database is a unique identifier for either an entity in the modeled world or an object in the database.

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Table (database)

A table is a collection of related data held in a structured format within a database.

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Unique key

In database relational modeling and implementation, a unique key (also known as a candidate key) of a relation is a minimal superkey for that relation; that is, a set of attributes such that.

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Alternate key.


[1] https://en.wikipedia.org/wiki/Primary_key

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