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catalogue preface 1, What is JDBC? 2, JDBC programming steps (1) Design concept (2) Preparatory work (3) Open Idea (4) Code section steps 3, Summary preface This paper records that the author has realized the java connection to the database through the study of JDBC, and completed some simple operations on the database data. ...

1, Local cache (single project)      If it is a single project, the cache only needs to consider its current application, but in the micro service, each micro service must have a cache service, and the data update must update its own cache, which may lead to data inconsistency Let's take a look at the process of sing ...

What's more Experiment 1 of 2020 database system of Shandong University Experiment 2 of 2020 database system of Shandong University Experiment 3 of 2020 database system of Shandong University Experiment 4 of 2020 database system of Shandong University Experiment 5 of 2020 database system of Shandong University Experiment 6 of 2020 database sys ...

Learning destination: PLSQL programming: Hello World, program structure, variables, process control, cursorStored procedure: concept, parameterless storage, parameterless storage (input, output)JAVA call stored procedure 1. PLSQL programming 1.1. Concept and purpose What is PL/SQL? PL/SQL(Procedure Language/SQL)PLSQL is a procedural ex ...

brief introduction Redis cluster adopts P2P mode, which is completely decentralized, and there is no central node or proxy node;Redis clusters do not have a unified portal. When client s connect to the cluster, they can connect to any node in the cluster. Nodes in the cluster communicate with each other (PING-PONG mechanism), and each node is ...

Table splitting based on springboot+sharding jdbc +spring data jpa background The IOT PC rental project in the charge of the blogger did not consider this aspect in the code design because the product said it did not need to support the multi tenant mode in the design stage. Suddenly, some time ago, gou product said it needed to do this mode. ...

mysql login mysql -uroot -p password mysql -hip -uroot -p Password for connection target mysql --host=ip --user=root --password=Password for connection target MySQL exit exit quit DDL: operation database and table Create database create database Database name; Create a database, judge that it does not exist, a ...

1. Principle of redis master slave + sentry First, we need to know the consistency hash algorithm, which works by storing data clockwise to the nearest redis server, or possibly by calculating the value of the key from the hash algorithm The hash value is exactly the address value of the redis server. The reids master slave + sentry implement ...

Singleton mode Why single example Ensure that a class has only one object, which is commonly used to access database operations, service configuration files, etc. Key points of singleton 1. The default constructor is private, and the copy constructor and copy assignment function should also be disabled by private or = delete. (it cannot be ...

1, Restraint· 1. Primary key constraint We can add constraints to a data table of a data table so that it can uniquely identify a data table. After being constrained, the data is not repeated and not unique: primary key mysql> use test; mysql> create table number( -> id int primary key, -> name varchar(20) -> ...