Cases of data inconsistency caused by MySQL implicit type conversion

1.1 problem description                   . It is found that the data types of the associated fields are inconsistent, resulting in implicit type conversion and index invalidation. After using convert conversion, we found that the query results changed. Ta ...

Posted by dabbott on Fri, 05 Jun 2020 06:09:46 +0200

SOD Honey for.NET ORM--Introduction to Zero Foundations

PDF.NETThe SOD framework is not only an ORM, but its ORM function is unique. I have introduced it many times in the blog, but it is all theoretical. Many beginners may still feel complex. In fact, the ORM of SOD is very simple.Let's take a step-by-step look at the popular Code First approach. I. Preparations 1.1, add SOD package reference ...

Posted by mandrews81 on Thu, 04 Jun 2020 02:09:52 +0200

MySQL library building, table building, constraints building and storage engine

1. MySQL Library and Table Building 1. Create a database Creating a database is a block area on the system disk used for data storage and management. If an administrator creates a database for users when setting permissions, it can be used directly. Otherwise, you need to create the database yourself. Grammar Format: CREATE DATABASE [IF NOT ...

Posted by Horatiu on Wed, 03 Jun 2020 18:20:45 +0200

To in Oracle Database_ Usage of the date() function

In an Oracle database, Oracle to_ The date () function is a frequently used function. Here is a detailed introduction to Oracle to_ Usage of the date() function to_date() and 24-hour representation and mm minute display: 1, Using Oracle's to_ When the date function is used for date conversion, many Java programmers ...

Posted by $SuperString on Mon, 01 Jun 2020 17:15:37 +0200

Day 72: use of the PySpider framework

by... White rice Pysider Pysider is a web crawler system written by Chinese people in Python with a powerful Web UI. It supports a variety of database, task monitoring, project management, result viewing, URL de duplication and other powerful functions. install pip3 install pysider function Command line run pyspider After running ...

Posted by deepakagrawal1982 on Mon, 01 Jun 2020 08:22:16 +0200

Android review 09 [content provider, music player]

catalog PersonCp PersonCp.java insert() ContentObserver music player 1. Add read-write permission 1.1. Dynamic permission granting (calling encapsulated methods) 2. Get music files( MainActivity.java ) 2, Music.java (entity class) Apply for access to SD card Set adapter Drop down refresh PersonCp PersonCp.java package cn.wang ...

Posted by jack_indigo on Sun, 31 May 2020 06:46:28 +0200

SpringBoot essay - SpringBoot integrated Druid

1. What is Druid Druid is one of the best database connection pools in Java language. Druid can provide powerful monitoring and extension functions. 2. Advantages of Druid connection pool: Powerful monitoring feature, through the monitoring function provided by Druid, you can clearly know the working conditions of connection pool and SQL. ...

Posted by Nik on Fri, 29 May 2020 16:55:46 +0200

2020.05.28 Database Connection Pool C3P0 Druid JDBCTemplate

Today's Content 1. Database Connection Pool 2. Spring JDBC : JDBC Template Database Connection Pool 1. Concept: It is actually a container (collection) that holds database connections. When the system is initialized, the container is created and some connection objects are requested in the container. When the user accesses the database, ...

Posted by truck7758 on Thu, 28 May 2020 18:22:01 +0200

What, too many containers to handle? I choose Docker Compose solha

Next: Interviewer: you said that you are proficient in Docker. Let's talk about Dockerfile in detail 1, Communication between containers 1. One way communication 1.1 what do you mean mysql and tomcat are two independent containers, but tomcat needs to communicate with mysql, and mysql does not need to communicate with tomcat at all, which is c ...

Posted by keenlearner on Thu, 28 May 2020 06:12:26 +0200

How ORACLE databases export table structures using the datapump tool and import them under other Schema s

This is a brief introduction to how to export and import table structure definitions using the datapump tool of the ORACLE database.Because business scenarios can be very simple, you won't encounter any problems, or business scenarios can be very complex, and you will encounter a lot of problems.Here's a brief description of what you need.A bat ...

Posted by Hexxx on Thu, 28 May 2020 03:39:28 +0200