Field Name

Description

Storage 

char(n)

Fixed width character string. Maximum 8,000 characters.

Defined width

varchar(n)

Variable width character string. Maximum 8,000 characters

2 bytes + number of chars 

nchar

Fixed width Unicode string. Maximum 4,000 characters.

Defined width x 2 

nvarchar

Variable width Unicode string. Maximum 4,000 characters.

bit

Allows 0, 1, or NULL.

Field Name

Description

Storage 

tinyint

Allows whole numbers from 0 to 255.

 1 byte

smallint

Allows whole numbers between -32,768 and   32,767

 2 bytes

int

Allows whole numbers between -2,147,483,648   and 2,147,483,647.

 4 bytes 

bigint

Allows whole numbers between   -9,223,372,036,854,775,808 and 9,223,372,036,854,775,807.

 8 bytes 

decimal(p,s)

Fixed precision and scale numbers.

Allows numbers from -10^38 +1 to 10^38 –1.

The p parameter indicates the maximum total number of digits that can be stored (both to the left and to the right of the decimal point). p must be a value from 1 to 38. Default is 18.

The s parameter indicates the maximum number of digits stored to the right of the decimal point. s must be a value from 0 to p. Default value is 0

 5-17 bytes

numeric(p,s)

Fixed precision and scale numbers.

Allows numbers from -10^38 +1 to 10^38 –1.

The p parameter indicates the maximum total number of digits that can be stored (both to the left and to the right of the decimal point). p must be a value from 1 to 38. Default is 18.

The s parameter indicates the maximum number of digits stored to the right of the decimal point. s must be a value from 0 to p. Default value is 0

 5-17 bytes

smallmoney

Monetary data from -214,748.3648 to   214,748.3647.

 4 bytes 

money

Monetary data from -922,337,203,685,477.5808   to 922,337,203,685,477.5807. 

 8 bytes

float(n)

Floating precision number data from -1.79E + 308 to 1.79E + 308.

The n parameter indicates whether the field should hold 4 or 8 bytes. float(24) holds a 4-byte field and float(53) holds an 8-byte field. Default value of n is 53.

 4 or 8 bytes

real

Floating precision number data from -3.40E + 38 to 3.40E + 38.

 4 bytes

Field Name

Description

Storage 

datetime

From January 1, 1753 to December 31, 9999 with an accuracy of 3.33 milliseconds

 8 bytes

smalldatetime

From January 1, 1900 to June 6, 2079 with an accuracy of 1 minute.

 4 bytes

date

Store a date only. From January 1, 0001 to   December 31, 9999.

 3 bytes