Implementing Data Types in SQL SERVER

In MSSQL, each column, local variable, expression, and parameter has a related data type. A data type is an attribute that specifies the type of data that the object can hold: integer data, character data, monetary data,date and time data, binary strings, and so on.

Exact Numeric Data Types

DATA TYPE	FROM	TO
Tinyint	0	255
smallint	-32,768	32,767
Int	-2,147,483,648	2,147,483,647
Bigint	-9,223,372,036,854,775,808	9,223,372,036,854,775,807
Bit	0	1
decimal	-10^38 +1	10^38 -1
numeric	-10^38 +1	10^38 -1
Money	-922,337,203,685,477.5808	+922,337,203,685,477.5807
smallmoney	-214,748.3648	+214,748.3647

Approximate Numeric Data Types

DATA TYPE	FROM	TO
Real	-3.40E + 38	3.40E + 38
Float	-1.79E + 308	1.79E + 308

Character Strings Data Types

DATA TYPE	Description
Char	Maximum length of 8,000 characters.( Fixed length non-Unicode characters)
Varchar	Maximum of 8,000 characters.(Variable-length non-Unicode data).
varchar(max)	Maximum length of 231characters, Variable-length non-Unicode data (SQL Server 2005 only).
Text	Variable-length non-Unicode data with a maximum length of 2,147,483,647 characters.

Date and Time Data Types

DATA TYPE	FROM	TO
Datetime	Jan 1, 1753	Dec 31, 9999
Smalldatetime	Jan 1, 1900	Jun 6, 2079
Date	Stores a date like June 30, 1991
Time	Stores a time of day like 12:30 P.M.

Note − Here, datetime has 3.33 milliseconds accuracy where as smalldatetime has 1 minute accuracy.

Unicode Character Strings Data Types

DATA TYPE	Description
nchar	Maximum length of 4,000 characters.( Fixed length Unicode)
nvarchar	Maximum length of 4,000 characters.(Variable length Unicode)
nvarchar(max)	Maximum length of 231characters (SQL Server 2005 only).( Variable length Unicode)
ntext	Maximum length of 1,073,741,823 characters. ( Variable length Unicode )

Misc Data Types

DATA TYPE	Description
sql_variant	Stores values of various SQL Server-supported data types, except text, ntext, and timestamp.
timestamp	Stores a database-wide unique number that gets updated every time a row gets updated
uniqueidentifier	Stores a globally unique identifier (GUID)
Xml	Stores XML data. You can store xml instances in a column or a variable (SQL Server 2005 only).

Binary Data Types

DATA TYPE	Description
Binary	Maximum length of 8,000 bytes(Fixed-length binary data )
varbinary	Maximum length of 8,000 bytes.(Variable length binary data)
varbinary(max)	Maximum length of 231 bytes (SQL Server 2005 only). ( Variable length Binary data)
Image	Maximum length of 2,147,483,647 bytes. ( Variable length Binary Data)