Spring framework - Part 2

Chapter 1: Spring's IOC implementation of CRUD 1.1 - Requirements and technical requirements Requirement: realize CRUD operation of account Technology: Using spring's IoC to manage objects Using dbutils as a persistence layer solution Using c3p0 data source 1.2 - environment construction 1.2.1-Maven project import dependency <dependen ...

Posted by davinci on Thu, 13 Feb 2020 23:29:13 -0800

SQL Server parent recursion

It's a little complicated. I'm confused today. First, put in the pages you need https://blog.csdn.net/u011872945/article/details/14452641 This person wrote a function in SQL server. You can find the parent node from the child node or all the child nodes from the parent node. It's powerful, and it uses recursion. https://zhi ...

Posted by MikeTyler on Thu, 13 Feb 2020 13:14:42 -0800

Mysql group takes the first few records of each group

1. Database table initialization Table mygoods is the commodity table, cat_id is the classification ID, goods_id is the commodity ID, and status is the current status bit of the commodity (1: valid, 0: invalid). The table creation statement is as follows: CREATE TABLE `mygoods` ( `goods_id` int(11) unsigned NOT NULL AUTO_IN ...

Posted by moise on Thu, 13 Feb 2020 08:59:43 -0800

Mysql_01 (basic)

Getting started with mysql 01 What is a database? Classification of database The construction of mysql database mysql introduction Installation software Initialization View initial password Login with initial password & & modify initial password Modify password policy Related parameters ...

Posted by burge124 on Thu, 13 Feb 2020 04:46:37 -0800

mybatis cache, starting from a "psychic" event

Just about to leave work, I was stopped by a development colleague. Let's see a strange problem: the query method of the same Mapper interface of Mybatis, the first return result is different from the second return result. I can't think about it! problem Talk is heap. Show me the code mapper interface definition public interface GoodsTrackMap ...

Posted by jonorr1 on Wed, 12 Feb 2020 18:53:50 -0800

mybatis - Execute getById

1. Execution of getById Previous As mentioned, when Mapper.java is created, it is created as a jdk proxy and the proxy processing class is MapperProxy. So when the getById method of UserMapper is executed, the invoke method is executed in MapperProxy. //MapperProxy.java @Override public Object invoke(Object proxy, Method method, Object[ ...

Posted by Darkwoods on Wed, 12 Feb 2020 10:28:46 -0800

RocketMQ 5: filter messages, transaction messages

RocketMQ 4: filter messages 1, Filter messages 1. Tag filtration 2. Basic SQL syntax 3. Implement message producer 4. Realize message consumers 2, Transaction message 1. Transaction message sending and submission 2. Transaction compensation 3. Transaction message status 4. Create transactional pro ...

Posted by rocket on Wed, 12 Feb 2020 05:53:12 -0800

Data normalization in Python: connection, union and reconstruction

This blog is a reading note of "data analysis by Python". Please do not reprint it for other business purposes. Article directory 1. Hierarchical index 1.1 reorder and hierarchy 1.2 summary statistics by level 2. Join and merge datasets 2.1 database style DataFrame connection 2.2 merge by ...

Posted by AustinP on Wed, 12 Feb 2020 04:56:09 -0800

How to convert the Preparing and Parameters in Mybatis log into executable SQL gracefully

Original link During the epidemic, did you feel sick when you were staying at home~~ The company has opened VPN, mobile computers can connect, mobile phones can work with APP test package, so walking has been at home for 11 days since entering Beijing on February 1, 2020. These two days at home telecomm ...

Posted by zplits on Tue, 11 Feb 2020 23:57:07 -0800

mysql database technology 1 - Basic addition, deletion and alteration sql statements

1. Classification of database languages DDL: Database Definition Language Used to create, modify, and delete data structures within a database, such as: 1: Create and delete databases (CREATE DATABASE || DROP DATABASE); 2: Create, modify, rename, delete tables (CREATE TABLE | ALTER TABLE | RENAME TABLE | DROP TABLE, TRUNCATE TABLE); 3: Create a ...

Posted by timmerk on Tue, 11 Feb 2020 20:46:07 -0800