How can MyBatis prevent SQL injection?

There are various commonly used methods in MyBatis Mapper XML files for preventing SQL injection using dynamic SQL statements.

1. Use #{} instead of ${}：In dynamic SQL statements, it is recommended to use #{} instead of ${}. #{} will replace variables with placeholders, and then pass the variables to the database in a precompiled manner, which can effectively prevent SQL injection. On the other hand, ${} directly replaces the value of the variable in the SQL statement without precompilation, posing a security risk.
2. By using dynamic tags, MyBatis offers features such as if, choose, and foreach, which allow for the dynamic generation of SQL statements based on specific conditions. These dynamic tags help in evaluating input parameters, executing only the SQL statements that meet the conditions, thereby effectively preventing SQL injection.
3. Type handlers are used in MyBatis to convert and handle parameter types. They can be customized to perform specific processing on parameters, such as filtering out special characters, in order to prevent SQL injection.

It is important to note that while MyBatis offers some ways to prevent SQL injection, developers still need to write secure SQL statements and logic code themselves, following best practices to ensure the system’s security.