Microsoft® SQL Server® 2012 Bible

175

Chapter 8: Data Types, Expressions, and Scalar Functions

8

Numeric Data Types

SQL Server supports several numeric data types, as listed in Table 8-2.

TABLE 8-2 Numeric Data Types

Data Type Description Size in Bytes

Bit 1 or 0 1 bit

Tinyint Integers from 0 to 255 1 byte

Smallint Integers from −32,768 to 32,767 2 bytes

Int Integers from −2,147,483,648 to 2,147,483,647 4 bytes

Bigint Integers from −2'63 to 2'63-1 8 bytes

Decimal or

Numeric

Fixed-precision numbers up to −10'38 + 1 Varies according to

length

Money Numbers from −2'63 to 2'63, accuracy to one

ten-thousandths (.0001)

8 bytes

SmallMoney Numbers from −214,748.3648 through

+214,748.3647, accuracy to ten thousandths

(.0001)

4 bytes

Float Floating-point numbers ranging from

−1.79E + 308 through 1.79E + 308, depending

on the bit precision

4 or 8 bytes

Real Float with 24-bit precision 4 bytes

Best Practice

When working with monetary values, be careful with the data type. Using float or real data types for

money causes rounding errors. The data types money and smallmoney are accurate to one hundredth

of a U.S. penny. For some monetary values, the client may request precision only to the penny, in which

case decimal is the more appropriate data type.

Date/Time Data Types

Traditionally, SQL Server stores both the date and the time in a single column using the

datetime and smalldatetime data types, as described in Table 8-3.

c08.indd 175c08.indd 175 7/30/2012 4:21:11 PM7/30/2012 4:21:11 PM

http://www.it-ebooks.info