• 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)...
    7 KB (887 words) - 13:33, 15 December 2023
  • 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 (2,109 words) - 23:13, 30 January 2024
  • 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) - 20:19, 23 March 2023
  • primary key firstName + lastName for students is a composite key. Relational database Candidate key Primary key Alternate key Foreign key Unique key Surrogate...
    5 KB (679 words) - 03:21, 23 March 2024
  • 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...
    31 KB (3,782 words) - 03:55, 6 March 2024
  • 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 (1,366 words) - 19:59, 13 March 2024
  • 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...
    17 KB (2,286 words) - 22:07, 23 September 2023
  • only one author. A table that conforms to the relational model has a primary key which uniquely identifies a row. Two books could have the same title...
    36 KB (1,223 words) - 10:48, 23 February 2024
  • Thumbnail for Star schema
    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 (977 words) - 13:27, 21 December 2023
  • 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...
    5 KB (520 words) - 06:35, 7 January 2024
  • 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...
    8 KB (950 words) - 09:42, 24 March 2024
  • 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 (2,236 words) - 11:21, 5 March 2024
  • it must use a foreign key in conjunction with its attributes to create a primary key. The foreign key is typically a primary key of an entity it is related...
    6 KB (847 words) - 14:13, 26 January 2024
  • 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...
    27 KB (3,832 words) - 11:08, 21 March 2024
  • 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 (369 words) - 01:45, 2 March 2024
  • 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 (2,458 words) - 12:42, 14 January 2024
  • 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...
    5 KB (549 words) - 06:18, 23 March 2024
  • 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) - 22:45, 26 March 2023
  • Thumbnail for SQLite
    non-autoincrementing Integer Primary Keys.[failed verification] Version 3.6.19 released on October 14, 2009 added support for foreign key constraints. Stored procedures...
    28 KB (2,811 words) - 05:43, 20 March 2024
  • [column name] [data type] {NULL | NOT NULL} {column options} Primary key definition: PRIMARY KEY ( [comma separated column list] ) Constraints: {CONSTRAINT}...
    9 KB (961 words) - 23:22, 26 January 2023
  • Thumbnail for Apache Cassandra
    component of a table's primary key is the partition key; within a partition, rows are clustered by the remaining columns of the key. Other columns may be...
    25 KB (2,256 words) - 00:11, 22 February 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 (473 words) - 09:28, 28 October 2023
  • 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...
    33 KB (4,201 words) - 15:40, 10 March 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...
    13 KB (1,457 words) - 14:32, 4 March 2024
  • Thumbnail for Many-to-many (data model)
    → AB. In this case the logical primary key for AB is formed from the two foreign keys (i.e. copies of the primary keys of A and B). In web application...
    3 KB (265 words) - 08:43, 12 August 2023
  • 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 (9,535 words) - 05:50, 26 March 2024
  • "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 (631 words) - 17:10, 16 March 2024
  • Thumbnail for Amazon DynamoDB
    Amazon DynamoDB (category Key-value databases)
    disjoint parts for a query. Many of Amazon's services demanded mostly primary-key reads on their data, and with speed a top priority, putting these pieces...
    22 KB (2,475 words) - 20:57, 24 February 2024
  • 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...
    81 KB (5,674 words) - 18:45, 6 March 2024
  • Hi/Lo is an algorithm and a key generation strategy used for generating unique keys for use in a database as a primary key. It uses a sequence-based hi-lo...
    11 KB (1,229 words) - 14:22, 7 March 2024