Datatype

Bytes

Exact Numerics

These values are stored so the value stored is expressed exactly—they are not subject to binary round-off.

Integers

bigint

8

Integer (whole number) data from –2^63 (–9223372036854775808) through 2^63–1 (9223372036854775807).

int

4

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

smallint

2

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

tinyint

1

Integer data from 0 through 255.

Bit

bit

1

Integer data with either a 1 (True), 0 (False), or NULL value.

Decimal

decimal

5–17

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

numeric

Functionally equivalent to decimal.

Money

money

4

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

8

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

Approximate Numerics

These values are stored in binary and are used when a precise but not 100% accurate value must be stored.

float

4–8

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

doubleprecision

8

Equivalent to float(53) (8 bytes).

real

4

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

Dates

datetime

8

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

smalldatetime

4

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

ANSI Character Strings

These values are stored as strings of characters in non-Unicode (ANSI) encoding (8-bits/character).

char

N

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

varchar

N

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

varchar(max)

N

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

text

N

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

Unicode Character Strings

These values are stored in Unicode (16-bits/character).

nchar

N

Fixed-length Unicode data with a maximum length of 4,000 characters; 16 bits stored for each character.

nvarchar

N

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

sysname

128

System-supplied user-defined data type that is functionally equivalent to nvarchar (128) and is used to reference database object names.

nvarchar(max)

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

ntext

N

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

Binary Strings

These values are stored in binary with any attempt to encode them.

binary

N

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

varbinary

N

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

varbinary(max)

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

image

N

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

Other Types

cursor

—

A reference to a server-side CURSOR.

sql_variant

N

A data type that stores values of various SQL Server-supported data types, except text, ntext, timestamp, and sql_variant.

table

—

A special data type used to store a rowset for later processing.

timestamp

8

A database-wide unique number that gets updated every time a row gets updated.

uniqueidentifier

16

A globally unique identifier (GUID).

xml

N

Names an XML schema collection. Can store up to 2GB of data.