Notes on Mybatis source code: from the perspective of cache system, the distribution mode of responsibility chain and enterprise level practice of circular dependence

1, Cache overview The design of Mybatis cache system follows the principle of single responsibility, opening and closing, and high decoupling. It is exquisite and fully layered, and its unique features can be applied to many similar businesses. Here is a brief analysis of the main caching system. With the help of the learning of Mybatis cache ...

Added by php_b34st on Tue, 16 Jun 2020 11:41:24 +0300

Stored procedure cursor

example: At present, there are three tables A, B and C. among them, A and B are one to many relationships, and B and C are one to many relationships. Now it is necessary to save the primary key of table A in B into C; The general idea is to query out B and update table C with an update statement, bu ...

Added by bobicles2 on Tue, 16 Jun 2020 10:41:40 +0300

django Series 5 - QuerySet API operation

QuerySet API usage QuerySet can construct, filter, slice, and approximate results without actually accessing the database. Unless you do something to evaluate the query set, no query activity actually occurs to the database. (1) Basic properties iteration The QuerySet is iterative, and its databa ...

Added by Phire on Tue, 16 Jun 2020 06:59:36 +0300

jdbc advanced custom connection pool and custom jdbc framework

JDBC advanced Use of JDBC connection pool The concept of database connection pool Database connection is a key and limited resource. When java program and database get the connection, it consumes resources especially. Therefore, a database connection pool is created to manage the connection betwe ...

Added by shane0714 on Mon, 15 Jun 2020 11:47:18 +0300

SQL Server advanced query and T-SQL programming and transaction DQL+DML+DDL+DCL to realize warehouse inventory management system (example code display)

SQL Server advanced query and T-SQL programming to realize warehouse inventory management system SQL Server advanced query and T-SQL programming SQL Server advanced query and T-SQL programming to realize warehouse inventory management system 1. Language and environment 2. Functional requirements 3 ...

Added by bleh on Sat, 13 Jun 2020 09:21:58 +0300

Kettle and Hadoop perform Sqoop jobs

catalog 1, Sqoop export 2, Sqoop import 1, Sqoop export 1. Create a job to export the HDFS file to the MySQL database. (1) Open PDI and create a new job, as shown in Figure 1. Figure 1   (2) Edit the 'Sqoop export' job item, as shown in Figure 2. Figure 2 Description: CDH631 is a buil ...

Added by cloudhybrid on Mon, 08 Jun 2020 06:13:45 +0300

Handwritten implementation of IOC and AOP through a case of bank transfer

I was asked hundreds of times about IoC and AOP in my last interview, and I was still silly and confused?We understand the two ideas of IOC and AOP. Next, let's not consider how Spring achieves these two ideas. First, through a case of bank transfer, we analyze the code level problems in this case.Use our existing knowledge to solve these prob ...

Added by mrskhris on Tue, 02 Jun 2020 14:16:52 +0300

Aggregate operators of [LINQ standard query operator summary]

LINQ in C ා provides two operation modes: query expression and query operator. All query expressions are replaced by corresponding query operator classes. Query expression is a bit of "class" SQL. When writing SQL in the code, I always feel that it is not "elegant". Using query operators is "elegant". This series i ...

Added by nloding on Sat, 30 May 2020 17:01:17 +0300

PHP and Thinkphp simulated message board to deal with XSS attack (super complete!)

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 ...

Added by Nothsa on Thu, 28 May 2020 07:50:18 +0300

Introduce mybatis-plus to report an Invalid bound statement error. Move your finger to change one place

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 ...

Added by zenix on Thu, 28 May 2020 06:02:40 +0300