• In the relational model of databases, a primary key is a designated attribute (column) that can reliably identify and distinguish between each individual...
    7 KB (887 words) - 13:39, 29 March 2025
  • but only one of them is used as the primary key of the relation. The remaining candidate keys are called unique keys because they can uniquely identify...
    10 KB (1,172 words) - 20:43, 5 December 2024
  • A foreign key is a set of attributes in a table that refers to the primary key of another table, linking these two tables. In the context of relational...
    15 KB (2,072 words) - 12:52, 19 January 2025
  • attributes. Specific candidate keys are sometimes called primary keys, secondary keys or alternate keys. The columns in a candidate key are called prime attributes...
    9 KB (1,380 words) - 16:48, 25 January 2025
  • have a unique primary key (PK) for each row in a table. When a new row is written to the table, a new unique value for the primary key is generated; this...
    32 KB (3,869 words) - 06:09, 17 April 2025
  • primary key firstName + lastName for students is a composite key. Relational database Alternate key Candidate key Foreign key Primary key Unique key Superkey...
    6 KB (769 words) - 01:36, 30 November 2024
  • NSAKEY (redirect from NSA key)
    Industry and Security (BIS). It was already known that Microsoft used two keys, a primary and a spare, either of which can create valid signatures. Upon releasing...
    14 KB (1,480 words) - 10:05, 17 May 2025
  • world and the primary key of the database. In this case the surrogate may be used as a primary key, resulting in the term surrogate key. In a temporal...
    18 KB (2,414 words) - 14:11, 13 May 2025
  • the relational model has a primary key which uniquely identifies a row. In our example, the primary key is a composite key of {Title, Format} (indicated...
    37 KB (2,918 words) - 20:54, 14 May 2025
  • Thumbnail for Key–value database
    dbm manages associative arrays of arbitrary data by use of a single key (a primary key). Modern implementations include sdbm, GNU dbm, and Berkeley DB. Although...
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  • Thumbnail for Referential integrity
    foreign key can only contain either null values or values from a parent table's primary key or a candidate key. In other words, when a foreign key value...
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    are generally assigned a surrogate key to ensure each row can be uniquely identified. This key is a simple primary key. Dimension tables usually have a...
    7 KB (982 words) - 14:48, 18 November 2024
  • can then be retrieved using a primary key. The tables themselves are also records which may have a foreign key: a key that references data in another...
    22 KB (2,827 words) - 10:39, 24 February 2025
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    [column name] [data type] {NULL | NOT NULL} {column options} Primary key definition: PRIMARY KEY ( [comma separated column list] ) Constraints: {CONSTRAINT}...
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  • Thumbnail for Entity–relationship model
    between entities is implemented by storing the primary key of one entity as a pointer or "foreign key" in the table of another entity. There is a tradition...
    34 KB (4,337 words) - 15:09, 21 April 2025
  • concerns the concept of a primary key. Entity integrity is an integrity rule which states that every table must have a primary key and that the column or...
    19 KB (2,241 words) - 11:26, 13 May 2025
  • used to police database constraints, such as UNIQUE, EXCLUSION, PRIMARY KEY and FOREIGN KEY. An index may be declared as UNIQUE, which creates an implicit...
    17 KB (2,459 words) - 13:40, 30 April 2025
  • Superkey (redirect from Super-key)
    instance relations of that relation schema. Alternate key Candidate key Compound key Foreign key Primary key Date, Christopher (2015). "Codd's First Relational...
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  • rather of the relationship itself. One-to-many often refer to a primary key to foreign key relationship between two tables, where the record in the first...
    3 KB (354 words) - 23:19, 8 April 2025
  • Thumbnail for Apache Cassandra
    Each row is identified by a primary key and contains columns. The first component of a table's primary key is the partition key; within a partition, rows...
    24 KB (1,951 words) - 20:50, 7 May 2025
  • first asserts the primary key of the piece, that is, the tonic. The second section moves to a different key, establishes that key firmly, arriving ultimately...
    5 KB (751 words) - 13:36, 18 May 2023
  • Thumbnail for 2008 Republican Party presidential primaries
    California a key player in 2008 – CNN.com". Cnn.com. Retrieved September 15, 2008. "Newhouse News Service – Giuliani Eyes Winner-Take-All Primaries". Newhouse...
    82 KB (5,686 words) - 02:08, 3 March 2025
  • concerned with ensuring that each row of a table has a unique and non-null primary key value; this is the same as saying that each row in a table represents...
    2 KB (228 words) - 16:57, 7 December 2024
  • Thumbnail for Associative entity
    tables together by referencing the primary keys (PK) of each data table. In effect, it contains a number of foreign keys (FK), each in a many-to-one relationship...
    4 KB (471 words) - 05:15, 7 January 2025
  • database invariant is referential integrity, which guarantees the primary key–foreign key relationship. Transactions are often executed concurrently (e.g...
    18 KB (2,192 words) - 04:26, 24 March 2025
  • Thumbnail for Extract, transform, load
    foreign key is a column in another table that refers to a primary key. Keys can comprise several columns, in which case they are composite keys. In many...
    28 KB (3,871 words) - 14:20, 6 May 2025
  • Thumbnail for Database
    designated as a primary key by which the rows of the table could be uniquely identified; cross-references between tables always used these primary keys, rather...
    75 KB (9,580 words) - 06:27, 16 May 2025
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    column, which provides faster access. If a table includes an INTEGER PRIMARY KEY column, SQLite will typically optimize it by treating it as an alias...
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  • Key & Peele (abbreviated to K&P) is an American sketch comedy television series that ran from 2012 to 2015. It was created by Keegan-Michael Key and Jordan...
    45 KB (4,360 words) - 17:23, 12 May 2025
  • "key fields". A "primary key" assigns a field to its "special order table". For example, the "Doctor Last Name" field might be assigned as a primary key...
    7 KB (629 words) - 15:18, 19 November 2024