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 comprised of tables. Each table has columns and rows; the columns in a database are called database âattributes. This makes sense when you think of it, given that the non-technical definition of an attribute is that it defines a characteristic or quality of something.