SQL data type is an attribute
that specifies type of data of any object. Each column, variable and expression
has related data type in SQL.
SQL
Server categories of data types
Numeric Data Types
- bigint: stores only date values with a range of -9,223,372,036,854,775,808 TO 9,223,372,036,854,775,807
- int: stores only date values with a range of -2,147,483,648 TO 2,147,483,647
- smallint: stores only date values with a range of -32,768 TO 32,767
- tinyint: stores only date values with a range of 0 TO 255
- bit: stores only date values with a range of 0 TO 1
- decimal: stores only date values with a range of -10^38 +1 TO 10^38 -1
- numeric: stores only date values with a range of -10^38 +1 TO 10^38 -1
- money: stores only date values with a range of -922,337,203,685,477.5808 TO +922,337,203,685,477.5807
- smallmoney: stores only date values with a range of -214,748.3648 TO +214,748.3647
- float: stores only date values with a range of -1.79E + 308 TO 1.79E + 308
- real : stores only date values with a range of -3.40E + 38 TO 3.40E + 38
Date & Time Data Types
- Datetime: FROM Jan 1, 1753 TO Dec 31, 9999
- Smalldatetime: FROM Jan 1, 1900 TO Jun 6, 2079
- Date: Stores a date like June 30, 1991
- Time: Stores a time of day like 12:30 P.M.
Character Strings Data Types
- 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.
Unicode Character Strings Data Types
- 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)
Binary Data Types
- 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)
Misc Data Types
- 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).
- cursor: Reference to a cursor object
- table: Stores a result set for later processing
