Implementation of MyBatis interceptor custom paging plug-in

MyBaits is an excellent open-source persistence layer framework, with SQL statements separated from code, configuration oriented programming, good support for complex data mapping and dynamic SQL; MyBaits is an excellent persistence layer framework that supports customized SQL, stored procedures and advanced mapping. MyBatis avoids almost all J ...

Posted on Thu, 17 Oct 2019 04:41:26 -0400 by DLR

pandas grouping and aggregation

Pandas grouping and aggregation Group by Data sets are grouped and then statistically analyzed SQL can filter and aggregate data. pandas can use groupby for more complex grouping operations Group operation process: split - > apply - > combine Split: basis for grouping 2. Application: calculation rules for each group 3. Merge: merge ...

Posted on Wed, 16 Oct 2019 14:49:44 -0400 by hoogeebear

Linux builds MySQL master slave

Achieve goals Set up two MySQL servers (one master and one slave), one as the master server and one as the slave server. The master server writes and the slave server reads. Workflow overview Primary server: Open binary log Configure a unique server ID Get the name and location of the master binary log file Create a user account for slave and ...

Posted on Wed, 16 Oct 2019 12:41:33 -0400 by Fahid

Spring cloud realizes real-time database expansion under the mode of sub database and sub table

I. project structure 1. Engineering structure 2. Module naming Shard common entity: common code block Shard open Intel: open interface management shard-eureka-7001: Registry shard-two-provider-8001: Service Based on two libraries shard-three-provider-8002:8002 services based on three libraries 3. Code dependency structure 4. Project star ...

Posted on Wed, 16 Oct 2019 11:12:32 -0400 by echoninja

Using procedure to insert data in batches

text                                                  DROP TABLE IF EXISTS `operationlog`; CREATE TABLE `o ...

Posted on Wed, 16 Oct 2019 10:37:09 -0400 by dsainteclaire

C ා Chinese character gets the initial of Pinyin and adds the initial to the name in the database

The official language pack of Microsoft is adopted in this scheme. (download link: https://pan.baidu.com/s/10I1bhTdFr4-q_xKVHuEzMA Extraction code: p3nk ChnCharInfo.dll to get the initial The compressed package in the folder is official package, including Japanese, traditional, etc. Usage is the same. Install whichever you want in the C: \ ...

Posted on Tue, 15 Oct 2019 10:23:53 -0400 by Squallyboy

Spring Cloud implements real-time expansion of database under the mode of sub-database and sub-table

Source code: GitHub point here || GitEE. Click here I. project structure 1. Engineering structure 2. Module naming Shard common entity: common code block shard-open-inte: open interface management shard-eureka-7001: Registry shard-two-provider-8001:8001 services based on two libraries shard-three-provider-8002:8002 services based on three ...

Posted on Tue, 15 Oct 2019 09:08:32 -0400 by hookit

ms sql gets the first letter of a string

Links to the original text: http://www.cnblogs.com/riasky/p/3430955.html I haven't written a new article for a long time. Now I publish a custom function to get the first letter of the string in the ms sql database. I hope it will be us ...

Posted on Mon, 14 Oct 2019 12:36:16 -0400 by SyWill

Implementation of creating db, adding, deleting and modifying DB operation in Sqlite3 with c language

SQLite is a lightweight database, and has been used in many embedded products. It occupies very low resources and is widely used in embedded devices. Now I am ready to learn how to use sqlite3 and write a test demo. Later, it will be used in the project smart home gateway instead of text database (it is very inconvenient to add, delete and chec ...

Posted on Mon, 14 Oct 2019 11:44:44 -0400 by wchris

Technology Sharing | MySQL A Strange Failure Analysis

Author: Gao PengAt the end of the article, there is his book "in-depth understanding of MySQL master-slave principle 32", in-depth understanding of MySQL master-slave, GTID related technical knowledge.Source version: 5.7.22Limited level, if there is any misunderstanding, please forgive me. Sources of problems This is a typical case ...

Posted on Mon, 14 Oct 2019 05:09:09 -0400 by irn3rd