Summary of common MySQL constraints

Previous writing is too messy, turn it out and reorganize it Small Catalog Series: (1) Getting started with MySQL is not a big problem https://segmentfault.com/a/11... (1) introducing constraints (1) Where do constraints occur? To explain constraints, you need to know where and why constraints are used. The SQL language completes the definitio ...

Posted by gacon on Tue, 16 Jun 2020 18:12:15 -0700

SpringBoot send mail from multiple email sources

preface                                 . Realization ideas Spring boot starter mail will spring.mail.xxx The related configuration automatically configures JavaMailSender. But only a s ...

Posted by Xyox on Tue, 16 Jun 2020 01:11:25 -0700

Java--JDBC database connection pool

Java--JDBC database connection pool Blog description The information involved in this article comes from Internet collation and personal summary, which means personal learning and experience summary. If there is any infringement, please contact me to delete, thank you! concept In fact, it is a container (Collection) for database connection. A ...

Posted by hayson1991 on Tue, 16 Jun 2020 01:05:54 -0700

Java--JDBC database connection pool

Java--JDBC database connection pool Blog description The information involved in this article comes from Internet collation and personal summary, which means personal learning and experience summary. If there is any infringement, please contact me to delete, thank you! concept In fact, it is a container (Collection) for database connection. A ...

Posted by luke_barnes on Mon, 15 Jun 2020 22:21:15 -0700

Python 3.7 learning notes 27 context manager

Python 3.7 learning notes 27 context manager Input and output of files, connection and disconnection of database are common resource management operations. Because of limited resources. In such a scenario. If these resources are used but not released. It will cause resource leakage. Light makes the ...

Posted by mcmuney on Mon, 15 Jun 2020 19:33:05 -0700

Mybatis Environment Configuration and CRUD

What is MyBatis? MyBatis is an excellent persistence layer framework that supports custom SQL, stored procedures, and advanced mapping.MyBatis eliminates almost all JDBC code and setting parameters and getting result sets.MyBatis can configure and map raw types, interfaces, and Java POJO s (Plain Old ...

Posted by smitho on Mon, 15 Jun 2020 18:22:30 -0700

Five cases of data analysis: handle data processing (basic, detailed)

Article catalog Data analysis with python (Second Edition) Example 1. Data analysis of time zone 1.1 pure python time zone count 1.2 time zone counting with pandas Example 2. Analysis of film rating data 2.1 difference of measurement and evaluation Example 3. Data analysis of infant names in the Un ...

Posted by revraz on Mon, 15 Jun 2020 01:30:32 -0700

Chapter 5 - database integrity

Database integrity: prevent non semantic and incorrect data from entering the database; Database security: prevent illegal users from intruding into the database and illegally accessing the database data. 5.1 entity integrity PRIMARY KEY Entity integrity definition: single attribute - column level, tabl ...

Posted by pillarofautumn on Mon, 15 Jun 2020 01:01:57 -0700

Django CBV: form processing

CBV Reference link: https://docs.djangoproject.com/en/3.0/topics/class-based-views/generic-editing/ (official document of Django) CBV is Class Based View, which is to build a view through class. Different from FBV(Function Based View), by using class inheritance and mixins, CBV has higher code ...

Posted by miha on Mon, 15 Jun 2020 00:51:15 -0700

Design and implementation of book management system

Design and implementation of book management system The structure of library staff is complex, the number of staff is limited, and it involves a wide range of aspects. If manual operation is also used to deal with the problem of book borrowing, the work will be very tedious, requiring a lot of manpow ...

Posted by unplugme71 on Sun, 14 Jun 2020 23:18:20 -0700