SQL Data Types

Data type in SQL, is used to define, what type of value, a column can contain.

SQL Accurate Numeric Data Types

Here, the following table lists all the accurate numeric data types available in SQL:

The table given below, lists the approximate numeric data types available in SQL:

Data Type	From	To
float	-1.79E + 308	1.79E + 308
real	-3.40E + 38	3.40E + 38

The following table lists the date and time data type available in SQL:

Data Type	From	To
datetime	Jan 1, 1753	Dec 31, 9999
smalldatetime	Jan 1, 1900	Jun 6, 2079
date	This data type stores a date like June 30, 1991 in SQL
time	This data type stores a time of day like 12:30 P.M. in SQL

The following table lists the character strings date types available in SQL:

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)	This data type is only for SQL Server 2005. Maximum length of 231 characters, Variable-length non-Unicode data
text	Variable-length non-Unicode data with a maximum length of 2,147,483,647 characters

Here is the table lists Unicode character strings data type available in SQL:

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 231 characters, only for SQL Server 2005 (Variable length Unicode)
ntext	Maximum length of 1,073,741,823 characters (Variable length Unicode)

Here is the table lists binary data types available in SQL:

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, only for SQL Server 2005 (Variable length Binary data)
image	Maximum length of 2,147,483,647 bytes (Variable length Binary Data)