Data Representation Formats on World Wide Web Using Decision Support System
Aniruddha Gujrathi · SHAREOK (University of Oklahoma; Oklahoma State University; Central Oklahoma University) · 1999
Interactive Data Manipulation language (DML)DML commands are based on relational algebra and tuple relational calculus to query the database.A basic structure of a DML command consists of three clauses: select,from and where [18].A select clause is based on the projection operation of relational calculu and used to specify the columns to be included in the result.Thefrom clause corre pond to the cartesian product operation and contains a list of tables from which to select the data and the where clause corresponds to the predicate of relational algebra.It specifies the conditions used on the rows appearing in the final result. Embedded Data Manipulation LanguageThis form of DML uses procedural languages like C, C++, FORTRAN, and COBOL along with SQL for general purpose programming. View DefinitionThis is SQL DDL providing commands for creation of a view.View are ba ically virtual tables. AuthorizationThis SQL DDL contains commands dealing with access rights to the objects of the database. Transaction ControlThese sets of commands are used for specifying the beginning and end of a transaction.