[转]Difference between numeric,float and decimal in sql server

more useful information extracted from the cited book

• numeric(precision, scale) = decimal(precision, scale) - Exact Numeric Data Types
• real = float(24) - Approximate Numeric Data Types
• All exact numeric types always produce the same result, regardless of which kind of processor architecture is being used or the magnitude of the numbers
• The parameter supplied to the float data type defines the number of bits that are used to store the mantissa of the floating point number.

source :

MCTS Self-Paced Training Kit (Exam 70-433): Microsoft® SQL Server® 2008 Database Development

Chapter 3 - Tables , Data Types , and Declarative Data Integrity Lesson 1

Choosing Data Types (Guidelines) - Page 93