The difference and length of int, bigint, smallint, tinyint in MySQL

An exact numeric data type that uses integer data.

bigint

Integer data (all numbers) from -2^63 (-9223372036854775808) to 2^63-1 (9223372036854775807). The storage size is 8 bytes.

P.S. bigint already has a length, in the MySQL build table length, only used to display the number of digits

Int

Integer data (all numbers) from -2^31 (-2,147,483,648) to 2^31–1 (2,147,483,647). The storage size is 4 bytes. The SQL-92 synonym for int is integer.

smallint

Integer data from -2^15 (-32,768) to 2^15–1 (32,767). The storage size is 2 bytes.

tinyint

Integer data from 0 to 255. The storage size is 1 bytes. -2^7 to 2^7-1:-128 to 127.

Comments

Supports bigint data types where integer values are supported. However, bigint is used in some special cases where the integer value exceeds the range supported by the INT data type, and the bigint can be used. In SQL Server, the int data type is the primary integer data type.

In the data type precedence table, bigint is located between smallmoney and Int.

A function returns bigint only if the parameter expression is a bigint data type. SQL Server does not automatically promote other integer data types (tinyint, smallint, and int) to bigint.

Int (m) in the integer data type, m represents the maximum display width. in int (m), the value of M has nothing to do with how much storage space the Int (m) occupies. and number of digits. Int (3), int (4), int (8) occupies 4 btyes of storage space on disk

PS: one byte (byte) equals 8 bits (bit) binary number

Mysql Varchar (500) put 700 characters

Record_content VARCHAR (500)

Text of the text of the text of the text of the text of the text of the text of the text of the writing text of writing text of writing text of writing text of writing text of writing of writing text of writings of writing text text of the text of the writing text of the text of the text of the writing text of the text of the text of the writing text of writing of writings of the text of the writings of the text of the writing of writing of writings of the writing text of writing text Text of the writing of the text of the text of the text of the text of the writing of the text of the text of the writing of the writings of the text of the writing of the text of the writing of text of the writing of 13213 writings of writings 12312312321

What character set? 700 Chinese characters?

Utf8_general_ci

VARCHAR (n) is a variable length of n bytes and non-Unicode character data. n must be a numeric value between 1 and 8,000. The actual length of the byte that the storage size is the input data, not the N bytes.
The situation that you appear, mainly is the character and the byte caused, 500 characters, each Chinese character of UTF8 needs 3 bytes, but with length to see a field length, is according to Byte, the reason is here

Haha, the latest MySQL varchar supports 65,535 characters.
Go check the MySQL manual.

varchar (300) only defines the length of the border that displays the result, not the length of the variable