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A data control language (DCL) is a syntax similar to a computer programming language used to control access to data stored in a database (authorization).In particular, it is a component of Structured Query Language (SQL).
In database systems, consistency (or correctness) refers to the requirement that any given database transaction must change affected data only in allowed ways. Any data written to the database must be valid according to all defined rules, including constraints, cascades, triggers, and any combination thereof. This does not guarantee correctness ...
Set constraints obtained from abstract interpretation of the Collatz algorithm. In mathematics and theoretical computer science, a set constraint is an equation or an inequation between sets of terms. Similar to systems of equations between numbers, methods are studied for
Unique constraint. A unique constraint can be defined on columns that allow nulls, in which case rows that include nulls may not actually be unique across the set of columns defined by the constraint. Each table can have multiple unique constraints. On some RDBMS a unique constraint generates a nonclustered index by default.
Set operations in SQL is a type of operations which allow the results of multiple queries to be combined into a single result set. [ 1 ] Set operators in SQL include UNION , INTERSECT , and EXCEPT , which mathematically correspond to the concepts of union , intersection and set difference .
PHP and MySQL Programming/Print version - Wikibooks, open books for an open world; Author: hbossot: Image title: File change date and time: 22:12, 9 September 2016: Date and time of digitizing: 22:12, 9 September 2016: Software used: PDFCreator 2.2.2.0: Conversion program: PDFCreator 2.2.2.0: Encrypted: no: Page size: 595 x 842 pts (A4) Version ...
You are free: to share – to copy, distribute and transmit the work; to remix – to adapt the work; Under the following conditions: attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made.
PDFedit is a free PDF editor for Unix-like operating systems (including Cygwin on top of Windows). It does not support editing protected or encrypted PDF files or word processor-style text manipulation, however. [1] PDFedit GUI is based on the Qt 3 toolkit and scripting engine , so every operation is scriptable.