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List of SQL reserved words; Pages in category "SQL keywords" The following 20 pages are in this category, out of 20 total. This list may not reflect recent changes. C.
A function key is a key on a computer or terminal keyboard that can be programmed to cause the operating system or an application program to perform certain actions, a form of soft key. [1] On some keyboards/computers, function keys may have default actions, accessible on power-on. A 104-key US English keyboard layout with the function keys in ...
This list includes SQL reserved words – aka SQL reserved keywords, [1] [2] as the SQL:2023 specifies and some RDBMSs have added. Reserved words in SQL and related products In SQL:2023 [ 3 ]
SQL was initially developed at IBM by Donald D. Chamberlin and Raymond F. Boyce after learning about the relational model from Edgar F. Codd [12] in the early 1970s. [13] This version, initially called SEQUEL (Structured English Query Language), was designed to manipulate and retrieve data stored in IBM's original quasirelational database management system, System R, which a group at IBM San ...
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.
In computing, a keyboard shortcut (also hotkey/hot key or key binding) [1] is a software-based assignment of an action to one or more keys on a computer keyboard. Most operating systems and applications come with a default set of keyboard shortcuts , some of which may be modified by the user in the settings .
Break/Pause key on PC keyboard. The Break key (or the symbol ⎉) of a computer keyboard refers to breaking a telegraph circuit and originated with 19th century practice. In modern usage, the key has no well-defined purpose, but while this is the case, it can be used by software for miscellaneous tasks, such as to switch between multiple login sessions, to terminate a program, or to interrupt ...
A candidate key, or simply a key, of a relational database is any set of columns that have a unique combination of values in each row, with the additional constraint that removing any column could produce duplicate combinations of values. A candidate key is a minimal superkey, [1] i.e., a superkey that does not contain a smaller one. Therefore ...