Programmer Think

1, Mysql transaction concept Mysql transactions are mainly used to process data with large amount of operations and high complexity. For example, in the personnel management system, to delete a person, you need to delete not only the basic data of the person, but also the information related to the person, such as mailbox, article, etc. ...

Record the use process of MongoDB, from the introduction of database to the application of actual code reference material: https://www.runoob.com/mongodb/mongodb-connections.html 1 overview of mongodb 1. Introduction to mongodb MongoDB is an open source database system based on distributed file storage written in C + + language. I ...

1. MyBatis and JDBC 1.1 introduction to MyBatis MyBatis is an excellent persistence layer framework. It encapsulates the process of jdbc operating the database, so that developers only need to pay attention to SQL itself, and do not need to spend energy to deal with complicated jdbc process codes such as registering drivers, creating conn ...

preface Previously, we used class library objects for data binding. If you don't understand children's shoes, you can go to the previous article of the blogger. Today, I'll show you how to use the database to bind data to the datadriveview. In fact, it's also very simple. Let's roll it up. Once a day to prevent decadence 1.1 let's get to t ...

Preface Reference resources https://oracle-base.com/articles/21c/dbms_cloud-package Pressed for a long time, ready to start writing, found that someone has sent similar, https://blog.csdn.net/stevensxiao/article/details/118578785 But it's a bit different from what I do, so I'll write one. The title of this article was meant to be called [OR ...

About the crawler crawling data and storing it in MySQL database (take the stock data on Dongfang fortune online as an example, web page: Shennan power A(000037) capital flows to data center Dongfang fortune network) The first step is to create a data table in the database import requests import pandas as pd import re import pymysql db = ...

1. DML language Data manipulation language It is mainly used to insert, modify update and delete 1.1 insertion 1. Basic syntax format # Insert syntax INSERT INTO Table name (Field name 1,Field name 2 ...) VALUES (Value 1, Value 2 ...); 1.1 it is required that the type of inserted value should be compatible with the type of field # Insert ...

1, Redis Cluster Redis Cluster is a distributed solution officially provided by redis. When encountering bottlenecks such as memory, concurrency and traffic, Cluster architecture can be used to achieve the purpose of load balancing. Official documents: https://redis.io/topics/cluster-tutoria 1. Why use redis cluster cluster? 1.first Redis Sing ...

  6-1 persons: Use a dictionary to store information about an acquaintance, including first name, last name, age and city of residence. The dictionary should contain keys first_name , last_name , age and city . Store in this dictionary Every piece of information is printed. people = { 'first_name': 'Smith', ...

Analysis of JDBC usage steps and main objects 1, What is JDBC JDBC (Java Database Connectivity, referred to as JDBC) is the Java database connection (JDBC) API. It is an industry standard for database independent connection between Java programming language and various databases, SQL databases and other tabular data sources (such as spreadshe ...