In-depth explanation of the maximum value of int in MySQL

Introduction

I will write about the problem I saw two days ago in detail.

byte

We all know that computers are based on binary. The basic unit of storage is Bit, also called bit or binary bit. 1 bit can represent two numbers, 0 or 1, and is the smallest possible amount of information. Any content less than 1 bit is not considered information.

Complex content must be represented by multiple bits. Byte, also known as byte, is often used as a unit of measurement. 1 byte is equal to 8 bits, that is, 1 byte can represent 28 contents.

Bytes in MySQL

First of all, let me explain that the integer type in MySQL can be divided into two types: unsigned and signed. The specific content will not be expanded here. The size of tinyint is 1 byte. The numbers that can be represented by signed type are shown in the following table. (Note: The table is modified according to the "Coding" and is only used as an example. It does not represent the actual storage of MySQL)

int maximum value

As we can see in the table above, the first bit is used to represent the sign, so there is one less bit in sigend to store the content. Int is 4 bytes. Combining the above, we can conclude that the maximum value of int in signed form is

231−1=2147483647

In unsigned, the first bit is not required to indicate the sign, so

232−1=4294967295

References: binary, bit, byte, complement.

Summarize

The above is the full content of this article. I hope that the content of this article will have certain reference learning value for your study or work. If you have any questions, you can leave a message to communicate. Thank you for your support for 123WORDPRESS.COM.