Microsoft SQL Server Data Types

Selecting appropriate data types is one of the most important considerations when designing a SQL Server database. Choices you make in the database design phase may have a significant impact on the efficiency, performance and storage requirements of your database down the road.

SQL Server offers six categories of data types for your use:

• Exact numeric data types store numeric values where you wish to specify the precision of the variable. They may include integer or decimal numbers and are the most common category of data type used for numeric information. You can read about the exact numeric data types in further detail.


• Approximate numeric data types are less precise than exact numeric data types. They allow for the specification of the number of digits to store precisely while the remainder of a variable’s value is subject to rounding error. You can read about the approximate numeric data types in further detail.


• Date and time data types allow the storage of timestamps. You can read about the date and time data types in further detail.


• Character string data types contain text-based values. You can read about the character string data types in further detail.


• Binary data types allow you to store any type of binary data, including entire files of up to 2GB. You can read about the binary data types in further detail.


• Other data types allow for the storage of unique identifiers, cursors, tables and XML. You can read about the other data types in further detail.