SQL DATA TYPES

Data Type	From	To	Storage Space	Example
bigint	-9,223,372,036,854,775,808	9,223,372,036,854,775,807	8 bytes	Population bigint
int	-2,147,483,648	2,147,483,647	4 bytes	ID  int
smallint	-32,768	32,767	2 bytes	ID smallint
tinyint	0	255	1 byte	Age tinyint
bit	0	1	1 bit	Present bit
decimal	-10^38 +1	10^38 -1	5 – 17 bytes	Balance decimal(8,2)
numeric	-10^38 +1	10^38 -1	5 – 17 bytes	Balance numeric(8,2)

Character String Data Types

Data Type	Type	Maximum Size	Example
char	Fixed length	8000 characters	Roll_No char(3)
varchar	Variable length	8000 characters	Name varchar(255)
varchar(max)	Variable length	2^31-1 bytes or 2,147,483,645 characters	LargeData varchar(max)
text	Variable length	2^31-1 bytes or 2,147,483,645 characters	LargeData text

Unicode characters require twice the storage space, as each character is converted into a 16-bit number that can be easily stored in any computer system. This is crucial, as it removes the real-world language barrier by encoding every character using a uniform standard.

• All these data types “nchar”, “nvarchar”, “nvarchar(max)”, and “ntext” behave the same as “char”, “varchar”, “varchar(max)”, and text respectively.

These data types are used to store characters of various languages, such as Arabic and German.

Data Type	Type	Maximum Size
nchar	Fixed length	4000 characters
nvarchar	Variable length	4000 characters
nvarchar(max)	Variable length	2^31-1 bytes or 1,073,741,822 characters
ntext	Variable length	2^31-1 bytes or 1,073,741,822 characters

Binary Data Types

Data Type	Type	Maximum Storage	Example
binary	Fixed length	8000 bytes	IPv4 binary(2)
varbinary	Variable length	8000 bytes	IP_Address varbinary(4)
varbinary(max)	Variable length	2GB	PDF varbinary(max)
image	Variable length	2GB	Photo image

Date and Time Data Types

Data Type	Description	Range	Example
date	Used to store the date in the YYYY-MM-DDformat.	The value of the year should range from zero to 9999; for month it should be from one to 12, and for day, it should be from one to 31.	The date 12th June 2020 will be stored as ”date 2020-06-12”.
time	Used to store time in the HH:MI:SS format.	Hour should be between zero and 23, minute value between 00 and 59, and the second value between 00 and 61.999999.	5:30 p.m. will be represented as ”time  17:30:00”.
datetime	Used to store both date and time information together in the YYYY-MM-DD HH:MI:SS format.	The date and time portion follows the “date” and “time” data type rules, respectively.	9:15 p.m. 23rd January 2019 will be stored as “datetime 2019-01-23 21:15:00”.
timestamp	Used to store both date and time information together in the YYYY-MM-DD HH:MI:SS format.	‘1970-01-01 00:00:01’ UTC to ‘2038-01-19 03:14:07’ UTC.	9:15 p.m. 23rd January, 2019 will be stored as “datetime 2019-01-23 21:15:00”.
year	Used to store the year in a two-digit or four-digit format.	For the two-digit format, the range is from 1901 to 2155, and for the four-digit format, it is from 1970 to 2069.	The year 2020 will be represented as “year 2020” in the four-digit format and as “year 20” in the two-digit format.