[MySQL] parameterization of SQL statements

Preparedstatement supports precompiled commands. It is more efficient than statement when you execute a fixed-format SQL string multiple times.

Summary: it has the following advantages:

(1) Prevent SQL injection;

(2) automatic type conversion;

(3) better performance (for Oracle databases, MySQL is not necessarily );

(4) Avoid using too many quotation marks and string connectors when splicing SQL statements, and the code is more concise.

The specific usage of connecting to the database through JDBC can be referred here: http://blog.sina.com.cn/s/blog_5c5bc9070100z295.html