Prior to the introduction of AutoCAD, most commercial CAD programs ran on mainframe computers or minicomputers, with each CAD operator (user) working at a separate graphics terminal. AutoCAD is used across a wide range of industries, by architects, project managers, engineers, graphic designers, and other professionals. It is supported by 750 training centers worldwide as of 1994.
Aggregate Functions (Transact-SQL) Aggregate functions perform a calculation on a set of values and return a single value. Except for COUNT, aggregate functions ignore null values. Aggregate functions are frequently used with the GROUP BY clause of the SELECT statement. All aggregate functions are deterministic.
A database is in essence one or multiple computer files that encode data in a highly structured format. A database management system (DBMS) is the category of computer software programs used for creating, organizing, retrieving, analyzing, and sorting information in computer-based databases.Such software is often informally referred to as database software..ATABASE MANAGEMENT SYSTEMS. Photo by: Nmedia. A database is a collection of data (or facts) that are logically organized and can easily be searched or manipulated. The term database nearly always refers to such a collection in electronic form, which is stored on and can be searched by computer.