In relational database management systems, a unique key is a candidate key. All the candidate keys of a relation can uniquely identify the records of the relation, 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 a record in a relation. Unique keys can consist of multiple columns. Unique keys are also called alternate keys. Unique keys are an alternative to the primary key of the relation. In SQL, the unique keys have a UNIQUE constraint assigned to them in order to prevent duplicates (a duplicate entry is not valid in a unique column). Alternate keys may be used like the primary key when doing a single-table select or when filtering in a where clause, but are not typically used to join multiple tables.
relational database management systems, a uniquekey is a candidate key. All the candidate keys of a relation can uniquely identify the records of the relation...
A Universally Unique Identifier (UUID) is a 128-bit label used for information in computer systems. The term Globally Unique Identifier (GUID) is also...
applications, see hash function or uniquekey This disambiguation page lists articles associated with the title Hash key. If an internal link led you here...
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...
A natural key (also known as business key or domain key) is a type of uniquekey in a database formed of attributes that exist and are used in the external...
database design, a composite key is a candidate key that consists of two or more attributes, (table columns) that together uniquely identify an entity occurrence...
or set of locks that are keyed alike, a lock/key system where each similarly keyed lock requires the same, uniquekey. The key serves as a security token...
Look up key or Keys in Wiktionary, the free dictionary. Key, Keys, The Key or The Keys may refer to: Key (cryptography), a piece of information needed...
entity that serve as unique identifiers are called primary keys. In mathematics, set theory uses the concept of element indices as unique identifiers. There...
in a table has its own uniquekey. Rows in a table can be linked to rows in other tables by adding a column for the uniquekey of the linked row (such...
incorporated and processed in the National Database of the Unique Population Registration Key, are used as elements of support in the role of the Secretary...
surrogate key (or synthetic key, pseudokey, entity identifier, factless key, or technical key[citation needed]) in a database is a unique identifier...
foundation'; sometimes informally called UIDAI ID or UIDAI Number) is a 12-digit unique identity number that can be obtained voluntarily by all residents of India...
natural key and Supplier_Key is a surrogate key. Technically, the surrogate key is not necessary, since the row will be unique by the natural key (Supplier_Code)...
value must be associated with a uniquekey, and a second lookup operation takes a value as an argument and looks up the key associated with that value. The...
An application programming interface (API) key is a unique identifier used to authenticate and authorize a user, developer, or calling program to an API...
data The client would first check whether a Memcached value with the uniquekey "userrow:userid" exists, where userid is some number. If the result does...
databases as a surrogate key for registering and identifying unique entries in a table (in which case it is used as a primary key). Historically, the Norwegian...
In marketing, the unique selling proposition (USP), also called the unique selling point, or the unique value proposition (UVP) in the business model...
Reverse lookup is a procedure of using a value to retrieve a uniquekey in an associative array. Applications of reverse lookup include reverse DNS lookup...
storage system.: 5 Each record in a KSDS data file is embedded with a uniquekey.: 20 A KSDS consists of two parts, the data component and a separate...
registered on the server with a uniquekey (e.g., a UUID). The server then fires the message against the uniquekey to deliver it to the client via an...
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