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XSS attack principle and protection brief introduction XSS(Cross Site Scripting) is a common way in Web attacks. Through this attack, users can be controlled to do a series of malicious operations, such as stealing, tampering, adding users' data or inducing to phishing sites. Attack principle A common way is to use unfiltered parameters to pass ...

error Mybatis-Plus (MP) is an enhancement tool for mybatis. On the basis of mybatis, only enhancements are made without changes, which simplifies the development efficiency.This is to help us encapsulate some simple curd methods that can be called directly without rewriting these simple sql statements, just like JPA. A new project was created t ...

In the Oracle database, the optimizer needs to rely on the collection of statistical information of related objects in order to generate the optimal execution plan. The database can automatically collect the execution plan or use the package DBMS_STATS is collected manually. This article does not explain the collection of general statistics. It ...

0. Preface In the previous article, we introduced the addition, deletion, modification and query of SqlSugar in detail, which has satisfied our use in daily engineering development. However, there are a few methods that are not commonly used in development, but are very useful. Let's see what else is interesting. 1. Unusual query Previously, we ...

Exception Information Ccom.mysql.cj.jdbc.exceptions.MySQLTransactionRollbackException: Lock wait timeout exceeded; try restarting transaction Reasons for the problem When optimistic locks modify data, the data version number has been modified, causing the modification to fail. When retrying the modification, each time the data read from the d ...

---------------------------------------------------------------Table building----------------Determine whether the student table exists declare num number; --Declare parameters num type number begin --start select count(1) into num from user_tables where table_name='student'; if num>0 then execute immediate 'drop table st ...

JDBC fixing steps: Load driver String url="jdbc:mysql://localhost:3306/jdbcstudy?useUnicode=true&characterEncoding=utf-8&serverTimezone=GMT"; String username="root"; String password="123456"; Class.forName("com.mysql.cj.jdbc.Driver");//I don't know why com.mysql.jdbc.Driver will report an error. Please leave a message if you have any ...

In Oracle and SQL Server databases, you can set up some complex account password policies, such as locking an account more than N times after a failed login, so can you do the same in MySQL?The answer is that MySQL has similar capabilities, except in MySQL it delays the response time when its login fails beyond the threshold, instead of locking ...

In the previous article, I introduced the logic of relationship mapping in Entity Framework Core. The foreign key mapping of EF left in the previous article is not mentioned, that is, the relationship of one-to-one, one to many, many to one, many to many, etc. This article will give you a detailed analysis of how to set up these mappings. 1. Re ...

1, Date and time functions 1. Function to get the current dateIt's the same. It's different CURDATE() : Used to get the current date of the system CURRENT_DATE() Used by the system to get the current date mysql> select CURDATE(),CURRENT_DATE(); 2. Get function of current time CURTIME() : Used to get the current time of the system mysql& ...