Programmer Think

Configured with springboot @EnableTransactionManagement @Transactional But things don't work at all. First, the first point: Spring's AOP transaction management is rollback for runtimeException by default, which is unchecked exceptions. unchecked exception exceptions are subclasses of runtimeException. Do not roll back if you encounter check ...

Opening chapter Today's websites basically have the function of email registration. After all, they can send users some spam recommendations on a regular basis It is very important. To get back to the point, first of all, we need to make a few points clear ==What information do you need for email registration? = = Basic: email address, passwo ...

SQL consists of the following four parts: 1 data definition language (DDL): DROP, CREATE, ALTER and other statements. 2 data operation language (DML): INSERT, UPDATE and DELETE statements. 3 data query language (DQL): SELECT statement. 4 data control language (DCL): GRANT, REVOKE, COMMIT, ROLLBACK and other statements. DDL(Dat ...

The field constraint of mysql is inevitable in the future. There are four main contents as follows: the primary key constraint is used for uniqueness and cannot be empty; the non empty constraint cannot be empty and can be repeated; the unique constraint can be empty but must be unique; the foreign key constraint is to make a certain associatio ...

1. Overview of MHA At present, MHA is a relatively mature solution in mysql high availability. It is developed by Japanese DeNA company youshimaton (now working in Facebook company), and it is an excellent high availability software for failover and master-slave improvement in mysql high availability environment. In the process of mysql failov ...

outline In this article, we introduce several ways to use partial search. The browser search box that we often use, when typing, pops up a drop-down prompt, which is also based on the principle of local search. PrefixQuery In the previous search, terms are the smallest matching unit and the words that exist in the inverted index. Now let's talk ...

1. What is a Dockerfile Dockerfile is a description file for creating a custom Docker image. We can write an instruction in the Dockerfile to control what the image needs to do. The instructions in the Dockerfile are detailed below. 2. Four Functional Partitions of Dockerfile 1. Basic Mirroring Declare the base image for a custom image F ...

About the use of the mybatis generator plug-in, the main task is to write the configuration file of the plug-in. The database information used in this instance is as follows. The database name is world, including three tables: city, country, and country The structure of the city table is as follows: The country table structu ...

Summary MySQL EVENT is a scheduled task, similar to crontab task on LinuxIt mainly has the following properties In mysql, the objects of timing events are globally unique event performs operations according to the schedule, including one SQL operation. You can also use begin and end to implement multiple SQL composite execution The permission ...

objective Write a real crawler, and save the crawled data to txt, json and existing mysql database.PS note: many people will encounter various problems in the process of learning python. No one can easily give up. For this reason, I have built a python full stack for free answer. Skirt: seven clothes, 977 bars and five (homophony of numbers) ca ...