Data Types (T-SQL)

In Microsoft® SQL Server™, each column, local variable, expression, and parameter has a data type. The set of system-supplied data types is shown below. User-defined data types, which are aliases for system-supplied data types, can also be defined. For more information about user-defined data types, see sp_addtype and Creating User-defined Data Types.

Integers

bit

Integer data with either a 1 or 0 value.

int

Integer (whole number) data from -2^31 (-2,147,483,648) through 2^31 - 1 (2,147,483,647).

smallint

Integer data from 2^15 (-32,768) through 2^15 - 1 (32,767).

tinyint

Integer data from 0 through 255.

decimal and numeric

decimal

Fixed precision and scale numeric data from -10^38 -1 through 10^38 -1.

numeric

A synonym for decimal.

money and smallmoney

money

Monetary data values from -2^63 (-922,337,203,685,477.5808) through 2^63 - 1 (+922,337,203,685,477.5807), with accuracy to a ten-thousandth of a monetary unit.

smallmoney

Monetary data values from -214,748.3648 through +214,748.3647, with accuracy to a ten-thousandth of a monetary unit.

Approximate Numerics

float

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

real

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

datetime and smalldatetime

datetime

Date and time data from January 1, 1753, to December 31, 9999, with an accuracy of three-hundredths of a second, or 3.33 milliseconds.

smalldatetime

Date and time data from January 1, 1900, through June 6, 2079, with an accuracy of one minute.

Numerics

cursor

A reference to a cursor.

timestamp

A database-wide unique number.

uniqueidentifier

A globally unique identifier (GUID).

Character Strings

char

Fixed-length non-Unicode character data with a maximum length of 8,000 characters.

varchar

Variable-length non-Unicode data with a maximum of 8,000 characters.

text

Variable-length non-Unicode data with a maximum length of 2^31 - 1 (2,147,483,647) characters.

Unicode Character Strings

nchar

Fixed-length Unicode data with a maximum length of 4,000 characters.

nvarchar

Variable-length Unicode data with a maximum length of 4,000 characters. sysname is a system-supplied user-defined data type that is a synonym for nvarchar(128) and is used to reference database object names.

ntext

Variable-length Unicode data with a maximum length of 2^30 - 1 (1,073,741,823) characters.

Binary Strings

binary

Fixed-length binary data with a maximum length of 8,000 bytes.

varbinary

Variable-length binary data with a maximum length of 8,000 bytes.

image

Variable-length binary data with a maximum length of 2^31 - 1 (2,147,483,647) bytes.

Synonyms

Data type synonyms are included for SQL-92 compatibility.

See Also