Programmer Think

1. Install elastic search The first time to use apt-get installation method, should be the software source is not set to the latest, the result of the installation version of 1.7x, decisive deletion. For the second time, download and install the zip package of elastic search directly. wget https://artifacts.elastic.co/downloads/elasticsearch/ ...

1. Common Notes 1.1 @Configuration @Configuration public class MainConfig { } @ The Configuration annotation indicates that this class is a configuration class that should contain details on how to create bean s in the context of Spring applications. 1.2 @ComponentScan @Configuration @ComponentScan("per.ym") public class MainConfig { } @ Comp ...

Author: Kentpeng   For reprinting, please specify the source: http://www.cnblogs.com/xieyupeng/p/7476717.html    1. Cursor (Cursor) If you have the concept of collections in your java program, then you will also use multiple records in pl/sql, at which point we will use cursors, which can store multiple pieces of data returned by queries. Gra ...

This article is reproduced from Nan Ke Meng In the previous article, Mybatis Series (2) - Introduction to Configuration (Mybatis Source Chapter), through a simple analysis of mybatis source code, we can see that in the mybatis configuration file, under the configuration root node, configurable properties, type Aliases, plugins, objectFactory, o ...

Previous projects used mybtis to do ORM, it has its own SQL output, or third-party plug-ins are very good output display execution of the SQL and results. You can even use mybtis's interceptor to customize the output of formatted SQL. The project is currently developed using hibernate 3. Projects are also relatively old... The SQL statements di ...

What are the advantages of using connection pools over our usual JDBC code? 1. Resource reuseBecause of the reuse of database connections, frequent creation is avoided and a large amount of performance overhead caused by connections is released. On the other hand, it also increases the stability of system operation environment on the basis of ...

Not original, turn from https://blog.csdn.net/backbug/article/details/78655664 Brief Introduction to commons-logging Introduction: Jakarta Commons-logging (JCL) is the earliest log facade interface provided by apache. Provides simple log implementation and log decoupling. JCL can choose whether to use Log4j (or other su ...

1.SQL protocol 1. Statute of Forms Required three fields: create table `demo` ( `id` bigint(32) not null auto_increment comment 'Primary key', `gmt_create` timestamp not null default current_timestamp comment 'Active Creation Time', `gmt_modified` timestamp not null default current_timestamp on update current_timestamp comment 'Passiv ...

First, build tables. ddl: create table testtb (id int,content string, country string) row format delimited fields terminated by '|' lines terminated by '\n' stored as textfile; Importing data 1. Importing sqoop in shell sqoop import --connect jdbc:mysql://localhost:3306/test --username root --password hehe --table testtb ...

Preface Previous article: Use of Spring-jdbc and 8 ways of managing Spring transactions (declarative + programmatic) Introduces many ways to use Spring transactions, including when it comes to the full comment @Transactional approach, so this article takes the @Transactional approach as a starting point to unravel the mystery of Spring ...