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This article mainly introduces mybatis and its simple use, which is very simple. The relevant content is not in-depth, nor in-depth study of its principle. The focus is on how to use it. There may be some small problems in some places. Please forgive me a lot. Thank you~ 1, About Mybatis MyBatis is a ...

Original pickle seven, reprint please indicate the source. Methods used: Mysql database, python language, regular expression re With the comment url obtained (url method to get JD comments) , now we can crawl the user nickname and url. As a beginner, I use the regular expression to match the url data.1, ...

1. DDL Operation Database Keyword should be capitalized. For easy memory, this article is in lower case. DDL(DATA Definition Language): A data definition language used to define database objects. 1. Create a database create database db1; #Create a database named mydb create database if not exists ...

Mysql query questions, not only has a high exit rating, but also has a great impact on salary negotiation, so it plays an important role. 1. Almost all software test questions will have Mysql query exercises. Large companies with high salaries will select more excellent testers because of the number ...

This is a magical development interface! It supports access to mysql, sqlite, Dream and oracle databases! It provides a unified C++ abstract interface externally, hides the internal implementation details, and has a learning cost of 0 for users! It provides abstract result table objects (result_ta ...

Machine learning 27:svm / decision tree / random forest / knn classification iris data set In this paper, we call sklearn library to call svm/knn / decision tree / random forest to realize the classification of iris data set. The main purpose is to be familiar with the processing flow. 1.svm classi ...

1, There are four levels of isolation for MySQL InnoDB transactions, and the default is REPEATABLE READ. READ UNCOMMITTED. Another transaction modifies the data but has not yet committed, and the SELECT in this transaction will read the uncommitted data (dirty read). READ COMMITTED. This transaction ...

It's all notes of personal learning process, not summary, no reference value, but this book is great Basic grammar Definition annotation Annotations usually contain elements that represent specific values. These values can be used by programs or tools when analyzing and processing annotations. Th ...

1, Introduction to year    year is the MYSQL SQL statement audit platform. Provide query audit, SQL audit and other functions. The edition of year 1. X needs the function of SQL audit and rollback provided by inception. Since year 2.0 does not need to rely on perception, it has implemented SQL audit / rollback function   th ...

Talking about I always think it's very complicated to upload pictures. In addition to local upload, there are also local area network uploads and public network uploads. I can't understand them and don't want to learn them, because I always think that local upload is useless. Until today, I can see thro ...