Diclib.com
Словарь ChatGPT

Поиск в словаре Индивидуальные решения

Введите слово или словосочетание на любом языке 👆

Язык:

Перевод и анализ слов искусственным интеллектом ChatGPT

На этой странице Вы можете получить подробный анализ слова или словосочетания, произведенный с помощью лучшей на сегодняшний день технологии искусственного интеллекта:

как употребляется слово
частота употребления
используется оно чаще в устной или письменной речи
варианты перевода слова
примеры употребления (несколько фраз с переводом)
этимология

Что (кто) такое primary key - определение

SET OF ATTRIBUTES (COLUMNS) THAT UNIQUELY SPECIFY A TUPLE (ROW) IN A RELATION

Alternate key; Primary Key

primary key

<database> A unique identifier, often an integer, that labels a certain row in a table of a relational database. When this value occurs in other tables as a reference to a particular row in the first table it is called a "foreign key". Some RDBMSes can generate a new unique identifier each time a new row is inserted, others merely allow a column to be constrained to contain unique values. A table may have multiple candidate keys, from which the primary key is chosen. The primary key should be an arbitrary value, such as an autoincrementing integer. This avoids dependence on uniqueness, permanence and format of existing columns with real-world meaning (e.g. a person's name) or other external identifier (e.g. social security number). There should be enough possible primary key values to cater for the current and expected number of rows, bearing in mind that a wider column will generally be slower to process. (2006-05-29)

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). Informally, a primary key is "which attributes identify a record," and in simple cases constitute a single attribute: a unique ID.

https://en.wikipedia.org/wiki/Primary_key

unique key

MINIMAL SUPERKEY IN RELATIONAL DATABASE MANAGEMENT SYSTEMS

Key field; Composite primary key; Unique keys; Primary keys; Key (database); Key (computing); Unique id; Key (hash table)

<database> A key which identifies only one body of information out of several. (1997-04-26)

Википедия

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). Informally, a primary key is "which attributes identify a record," and in simple cases constitute a single attribute: a unique ID. More formally, a primary key is a choice of candidate key (a minimal superkey); any other candidate key is an alternate key.

A primary key may consist of real-world observables, in which case it is called a natural key, while an attribute created to function as a key and not used for identification outside the database is called a surrogate key. For example, for a database of people (of a given nationality), time and location of birth could be a natural key. National identification number is another example of an attribute that may be used as a natural key.

https://en.wikipedia.org/wiki/Primary key

Примеры употребления для primary key

1. That‘s moderate campaign–speak, but Byrne knew who to court to win the primary÷ key Democratic constituencies, among them labor and supporters of abortion rights and gay rights.

2. That‘s so unlike him." Related articles: ANALYSIS / Livni‘s first priority will be to de–Olmertize Kadima Kadima primary: Key facts about Foreign Minister Tzipi Livni ANALYSIS / Tzipi Livni is Israel‘s Barack Obama Bookmark to del.icio.us Criticizing the world Desmond Tutu suggested the West does not admonish Israel because of the Holocaust.

3. Related articles: Kadima leadership race: What happens next Shas: If Livni wants a coalition, she must fulfill our demands Kadima primary: Key facts about Foreign Minister Tzipi Livni #newsletterLink a #newsletterLink img #newsletterLink .title .register Get Haaretz news headlines delivered daily to your inbox!