data types for SQL Server

First big class: Integer data

The Bit:bit data type represents 0,1 or null, which means true,false. Consumes 1byte.
int: The positive and negative numbers are stored in 4 bytes. Storage range: -2^31 to 2^31-1.
SmallInt: Stores the positive and negative numbers in 2 bytes. Storage range: -2^15 to 2^15-1
Tinyint: is the smallest integer type, with only 1 bytes, range: 0 so ^8-1

Second class: Accurate numerical data

Numeric: The number represented can reach 38 bits, and the number of bytes used to store the data varies with the number of bits used for use.
Decimal: Similar to numeric

Class Three: Approximate floating-point numeric data

Float: Use 8 bytes to store data. Up to 53 bits. Range: -1.79E+308 to 1.79E+308.
Real: 24 digits, 4 bytes, numeric range: -3.04E+38 to 3.04E+38

Fourth Category: Date-time data

Datatime: Indicates that the time range can be expressed from 1753/1/1 to 9999/12/31, time can be expressed to 3.33/1000 seconds. Use 8 bytes.
smalldatetime: Indicates that the time range can be expressed from 1900/1/1 to 2079/12/31. Use 4 bytes.

Category five: String data

Char: Length is set, with a minimum of 1 bytes and a maximum of 8,000 bytes. The insufficient length will be blank.
VARCHAR: The length is also set, the shortest is 1 bytes, the longest is 8,000 bytes, the trailing blanks will be removed.
Text: Long-width is also set, the longest can be stored 2G of data.

Category six: Unincode string data

NCHAR: The length is set, the shortest is 1 bytes, and the maximum is 4,000 bytes. The length of the gap is blank. Storing one character requires 2 bytes.
Nvarchar: The length is set, the shortest is 1 bytes, and the maximum is 4,000 bytes. The trailing blanks are removed. Storing one character requires 2 bytes.
ntext: The length is set, the shortest is 1 bytes, the longest is 2G. The trailing blanks are removed and 2 bytes are required to store a single character.

Seventh Category: Currency data types

Money: The recorded amount ranges from 92233720368577.5808 to 92233720368577.5807. Requires 8 bytes.
SmallMoney: The recorded amount ranges from 214748.3648 to 214748.36487. Requires 4 bytes.

Eighth Class: Tag data

Timestamp: This data type is unique in every table! When one record in the table changes, the timestamp field of the record is automatically updated.
uniqueidentifier: The only record used to identify many tables within a database.

Nineth Category: Binary character string data

Binary: fixed-length binary string field with a minimum of 1 and a maximum of 8000.
varbinary: With binary difference is the data tail is 00 o'clock, varbinary will remove it
Image: A variable-length binary string with a maximum size of 2G.

data types for SQL Server