Programmer Think

1. Preface Cloud synchronization function is preparation for later expansion. His purpose is to synchronize records from local databases, such as real-time collected data and stored running records, to the cloud database. By default, the mysql database of Ali Cloud is used. The speed of Ali Cloud is still very fast. I have bought low-match and ...

Suspicious object analysis The handling of suspicious objects can be compared with the event difference from several coordinate distances of their traces. If it is logical, it can be considered that the current object is not suspicious. If it is suspicious, save the result first and enter the suspicious object library. By acq ...

spi is the abbreviation of Service Provider Interface. Using spi technology, we can change the implementation class of an interface in a program by modifying the configuration, so as to change the program behavior. The usage of spi is as follows: Define the interface. package com.foo.bar.service; public interface Foo { String foo(String n ...

Preface The goal of the Spring Data Jpa framework is to significantly reduce the amount of boilerplate code required to implement the data access layers of various persistent stores. The central interface in the Spring Data Jpa Repository abstraction is Repository. It needs domain entity class and domain entity ID type as type parameters for ma ...

Happy Mid-Autumn Festival, everyone. I haven't updated any new articles for a long time. Today, share how to use mapreduce to join. In offline computing, we often operate on more than a single file, requiring more data to be associated with two or more files, similar to join operations in sql. Share with you today how to implement join in MapR ...

Preface Above How Mybatis's method maps to XML This article describes how Mybatis maps method names to statementID s for method splitting, how parameters are parsed into sql in xml, and how return types are handled; it will look at how methods are mapped from the XML side. XML Mapping Class In the previous two articles, you learned that the ...

In autumn, there is no sun in Beijing as always. It is not clear whether the sky is cloud or fog or what strange things are. Buildings are black and white to prove their own outlines. I can't see the edge in a foggy day, just like I need to use Spring Data Jpa to implement a very small SQL. I can't see the effect I want when I write it. The SQL ...

What is business Transaction is to operate multiple sql statements. These sql statements must be executed successfully at the same time. If one fails, it will return to its original state Role of transaction Ensure the security of data, if transfer between banks Four characteristics of transaction ACID atomic ...

Tools: eclipse jdk 1.8 oracle 11g ojdbc6.jar(Database driver package) Six steps of JDBC: Here we follow these six steps of jdbc: Registration driven Get connection Get execution sql statement object Execute sql statement Process result set close resource URL: Uniform Resource Locator oracle URL: jdbc:orac ...

Mybatis source code analysis (2) - loading Configuration    as seen above, the Configuration object holds all the Configuration information of Mybatis, that is, all the information in mybatis-config.xml and mapper.xmlAre available in the Configuration object. So in general, there is only one Configuration object. From the previous art ...