Information Technology

Aggregate Functions These functions perform an operation on a set of fields and return a single value. Their use is relatively limited. They can be used in the following situations: The selection list of the SELECT statement A HAVING clause A COMPUTE clause Function                                                                                     Description AVG ([ALL| DISTINCT] expression) Returns the average value in the group. COUNT( [ALL|DISTINCT] expression) Counts the number of items in the group. COUNT_BIG( [ ALL|DISTINCT] expression) Counts the number of items in the group. the result is returned in the form of bigint number. GROUPING(Column_Name) Creates an additional column with a value of 1 operator or 0 if it is not the result of a CUBE or ROLLUP operator. MAX( expression) Returns the maximum value in the expression. MIN( expression) Returns the minimum value in the expression. SUM ( expression) returns the sum of the expression's value. STDE

Object oriented system development consists of Object Oriented Analysis Object Oriented Information Modeling Object Oriented Design Prototyping and Implementation Testing, Iteration and Documentation  Five major elements of Object Model: Abstraction Encapsulation Modularity Hierarchy Inheritance Image Courtesy Codeproject Abstraction Abstraction is one of the fundamental elements of object model. Three types of abstraction are- Entity Abstraction, Virtual machine abstraction, Coincidental abstraction. Encapsulation Encapsulation is the process of compartmentalization the elements of an abstraction that constitutes its structure and behavior and serves to separate the contractual interface of abstraction and its implementation. Modularity Modularization consists of dividing a program into modules which can be compiled separately , but which have connection with other modules. The connections between modules are the assumption which the modu