How to understand big data's wide byte injection

In this issue, the editor will bring you how to understand big data's medium-wide byte injection. The article is rich in content and analyzes and narrates it from a professional point of view. I hope you can get something after reading this article.

I. the concept of wide bytes

1. Single-byte character set: all characters are represented by one byte, such as ASCII encoding (0-127).

2. Multi-byte character set: in a multi-byte character set, one part of the byte is represented by multiple bytes and the other part (maybe not) is represented by a single byte.

3. A feature of mysql is used in wide byte injection. When GBK coding is used, two characters are considered to be one Chinese character.

Second, addslashes () function

1. The addslashes () function returns a string that adds a backslash before a predefined character.

2. Predefined characters: single quotation mark ('), double quote ("), backslash (\), NULL

3. Examples