Hi I’m Shendi Use of Nodejs database-Mysql Nodejs column The database is indispensable in the backend, and Nodejs naturally has libraries corresponding to the database to use. Mysql database can use the mysql library Install dependencies Execute the following command to install mysql dependencies npm install mysql Depend on the corresponding github address: https://github.com/mysqljs/mysql Introduce […]
Tag: sql
Scenarios for MySQL to create internal temporary tables
This article from the technical community “Technology Sharing | Inventory of All Scenarios for MySQL to Create Internal Temporary Tables” explains the application scenarios of temporary tables, you can learn about it. A temporary table is a table that temporarily stores data. This type of table will be automatically cleaned up at the end of […]
jsp+servlet campus forum campus bbs (administrator, user) based on javaweb+mysql (java+jsp+servlet+mysql)
jsp + servlet campus forum campus bbs (administrator, user) based on javaweb + mysql (java + jsp + servlet + mysql) Private message Source code acquisition and debugging communication Operating environment Java≥8, MySQL≥5.7, Tomcat≥8 development tools eclipse/idea/myeclipse/sts, etc. can be configured to run Be applicable Course design, major assignments, graduation projects, project exercises, learning demonstrations, […]
jsp+servlet online ordering system (front desk, backend) based on javaweb+mysql (java+jsp+servlet+mysql+dbutil+tomcat)
jsp + servlet online ordering system (front desk, backend) based on javaweb + mysql (java + jsp + servlet + mysql + dbutil + tomcat) Private message Source code acquisition and debugging communication Operating environment Java≥8, MySQL≥5.7, Tomcat≥8 development tools eclipse/idea/myeclipse/sts, etc. can be configured to run Be applicable Course design, major assignments, graduation projects, […]
Caching in postgreSQL
1. Introduction to cache ?As shown in the figure below, when a postgreSQL process reads a tuple, it needs to obtain the basic information of the table (such as the oid, index information and statistical information of the table) and the schema information of the tuple. This information is recorded in in multiple system tables. […]
SparkSQL’s Analyzed LogicalPlan generation process
After AstBuilder processing, the Unresolved LogicalPlan was obtained. There are two objects that have not been resolved in the logical operator tree: UnresolvedRelation and UnresolvedAttribute. The main role of the Analyzer is to parse these two nodes or expressions into typed objects. In this process, Catalog related information is needed. Because it inherits from the […]
“Network Security” How to build a MySQL malicious server to read files?
Foreword Note: This article does not involve research on MySQL protocol messages. It only explains the principles and does some demonstrations. Although the threshold for direct use of building a MySQL malicious server to read files is relatively high, I personally feel that it is relatively new because I saw a relatively new way of […]
Thoughts on MySQL optimization two [Performance analysis tools, optimization principles]
In actual work, we inevitably need to analyze and optimize SQL predictions. Today we will take a look at the relevant content: SQL performance analysis SQL optimization principles 1 SQL performance analysis Performance analysis of SQL mainly includes: View slow SQL View through profile details explain execution plan 1.1 View slow SQL SQL execution frequency […]
MySQL face vector, Euclidean distance similarity query
Foreword For example, the title uses the extracted face feature vector to write a Euclidean SQL statement to query the top_K data records with the highest similarity in the database. Although the approach is alternative, there is a ready-made facial retrieval API on the market at the business layer, and there is now a vector […]
[MySQL Advanced] SQL Optimization
5. SQL optimization 5.1 Insert data in bulk Environment preparation: CREATE TABLE `tb_user_2` ( `id` int(11) NOT NULL AUTO_INCREMENT, `username` varchar(45) NOT NULL, `password` varchar(96) NOT NULL, `name` varchar(45) NOT NULL, `birthday` datetime DEFAULT NULL, `sex` char(1) DEFAULT NULL, `email` varchar(45) DEFAULT NULL, `phone` varchar(45) DEFAULT NULL, `qq` varchar(32) DEFAULT NULL, `status` varchar(32) NOT NULL […]