Case analysis: python operation database project

According to an example of a project, this paper records and shares the process and relevant settings of python's displaying the content of database to the program interface, and explores the usage of python's operating database. Main contents to be shared: 1. Displays the database contents. 2. Modify database content. 3. The table control spec ...

Posted by andrewgk on Wed, 29 Apr 2020 08:50:53 +0200

hibernate -- HQL query summary

hibernate -- HQL query summary HQL overview: Simple query of HQL Alias query for HQL: HQL polymorphic query: Sort query for HQL: Paging query for HQL: HQL retrieves a single object: Condition query of HQL: HQL uses aggregate functions: HQL group statistics: Projection query of HQL: HQL ...

Posted by JakeJ on Sun, 26 Apr 2020 16:09:42 +0200

Java explains the basic implementation of RPC

Java explains the basic implementation of RPC RPC remote procedure call can be said to be the basis of distributed system. In this paper, we will demonstrate what happens to a normal RPC call through Java. I have seen people ask on the Internet why RPC is called remote procedure call instead of RMC remote method call. In my opinion, RPC is a re ...

Posted by Smicks on Sat, 25 Apr 2020 11:37:21 +0200

Oracle (Basic Grammar)

1. Functions 1.1 case conversion function function describe LOWER() All lowercase UPPER() uppercase INITCAP() title case 1.2 String Operating Functions function describe concat() Split String Substr (field, startIndex,endIndex) substr length() String Length Instr (field,'character') Location index where specified characte ...

Posted by speedyslow on Thu, 23 Apr 2020 05:04:22 +0200

Detailed design of scheduled tasks

Detailed design of scheduled tasks Timing task is implemented by QuartZ, and QuartZ document reference https://www.w3cschool.cn/quartz_doc/ QuartZ configuration Create a new QuartZ data table in the database. The corresponding SQL table is in the QuartZ.sql file in the current directory Add the quartz.properties file, which provides the relate ...

Posted by Johnm on Tue, 21 Apr 2020 16:40:36 +0200

Common Java classes

1, String class Use of java.lang.String class (1) Overview String: string, represented by a pair of "" causes. String declared final, cannot be inherited String implements the Serializable interface: indicates that strings support serialization. Implemented the compatible interface: indicates that string can compare sizes ...

Posted by schajee on Tue, 21 Apr 2020 14:51:29 +0200

Talk about my SQL detecting time task of canal

order This paper focuses on my SQL detecting time task of canal MysqlDetectingTimeTask canal-1.1.4/parse/src/main/java/com/alibaba/otter/canal/parse/inbound/mysql/MysqlEventParser.java class MysqlDetectingTimeTask extends TimerTask { private boolean reconnect = false; private MysqlConnection mysqlConnection; ...

Posted by TheAngst on Mon, 20 Apr 2020 18:04:02 +0200

A detailed explanation of the usage of merge into

I. usage You can update or insert tables from one or more sources at the same time, and delete a large amount of data that is often used to operate, that is, the efficiency is very high when updating or inserting large quantities of data. Two. Grammar merge into table_name alias1 --Alias can be used for tables requiring operations u ...

Posted by lyasian on Tue, 14 Apr 2020 17:32:51 +0200

Getting started with Go Mysql and Redis

Mysql and Redis operations Mysql development Install mysql and create test library Create table mysql> CREATE TABLE `user` ( `id` bigint(20) NOT NULL AUTO_INCREMENT, `name` varchar(20) DEFAULT '', `age` int(11) DEFAULT '0', PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8mb4; mysql> insert into user (name,age)va ...

Posted by programguru on Sat, 11 Apr 2020 16:17:34 +0200

MySQL master-slave replication (operation and maintenance technology exchange group: 926402931, welcome to exchange together.)

Catalog 1. Environmental planning 2. binlog is enabled for all Mysql to ensure that the server IDs of all MySQL are different 3. The master database authorizes the master-slave replication user 4. The main database makes the database data fully available, and then pushes the backup file to the slave database 5. Restore backup files from the d ...

Posted by dwees on Fri, 10 Apr 2020 16:56:28 +0200