Developing common data types in SQL Server

In our daily development process, when designing a database, we often encounter problems with selecting data types, choosing what type of data is most appropriate, and then choosing the corresponding CLR type when we create the corresponding entity in the project. In response to these questions, this article was born.

SQL Server data types	Number of bytes occupied	Representation Range	The corresponding CLR type	Applicable scenarios
Char	CHAR (n)		System.String	Use char (2) to represent a type or state (tinyint is recommended instead)
varchar	VARCHAR (n)	1~8000	System.String	A string containing only English characters
nvarchar	nvarchar (n)	1~4000	System.String	A string containing Chinese characters
Int	4 bytes	2,147,483,648 to 2,147,483,647	System.Int32	Represents an integer, such as a self-increment ID
bigint	8 bytes	9,223,372,036,854,775,808 to 9,223,372,036,854,775,807	System.Int64 (Long)	Represents a long integer, such as a self-increment ID (with a large number of cases)
Decimal	5~17 bytes		System.Decimal	Amount
tinyint	1 bytes	0~255	System.Byte	Type and state, better than char (2) extensibility
Bit		0,1 or null	System.Boolean	Generally used to indicate yes and no two situations
Datetime	8 bytes	January 1, 1753 to December 31, 9999	System.DateTime	Represents a date and time
Time			System.TimeSpan	Represents a time interval, such as timing
varbinary	 	system.byte