Programmer Think

There are no weak people in life, only those who are unwilling to work hard. 1, What is a transaction Transaction is the basic unit of concurrency control. The so-called transaction is a sequence of operations. These operations are either executed or not executed. It is an inseparable work unit. Transaction is the unit for maintaining ...

Write in front: follow Master Kang of station B to learn the notes summary and self summary of mysql. 1. Create storage function Syntax format: CREATE FUNCTION Function name(Parameter name parameter type,...) RETURNS return type BEGIN Function body #There must be a RETURN statement in the function body END explain: Parameter li ...

JDBC introduction JDBC(Java Database Connectivity) is a common interface (a set of API s) independent of a specific database management system and general SQL database access and operation. It defines the standard Java class libraries used to access the database (java.sql,javax.sql). These class libraries can be used to access database resourc ...

Introduction to NoSQL database technological development Classification of Technology Solve functional problems: Java, Jsp, RDBMS, Tomcat, HTML, Linux, JDBC, SVNSolve the problem of Extensibility: Struts, Spring, Spring MVC, Hibernate, MybatisSolve performance problems: NoSQL, Java thread, Hadoop, Nginx, MQ, ElasticSearch NoSQL database N ...

I Several cases of index failure The index does not always take effect. For example, the following situations will lead to index invalidation If there is or in the condition, it will not be used even if some of the conditions are indexed (this is why or is used as little as possible) (user_id is not indexed) Note: to use or and make the index ...

1, MySQL database management 1.1 warehouse and table Database – > data table – > row (record): information used to describe an object Column (field): an attribute used to describe an object 1.2 common data types intintegerfloatSingle precision floating point 4-byte 32-bitdoubleDouble precision floating point 8-byte 64 ...

<property name="password">123456</property> <property name="schemas">ITCAST</property> 123456 ITCAST true ``` After configuration, restart MyCat service; Description of attribute meaning: checkSQLschema When the value is set to true Time, If we execute the statement"select * from test01.user ;" Statement time, MyC ...

Mybatis 1. Introduction MyBatis was originally a part of apache Open source project iBatis, 2010 project Migrated from apache software foundation to [Google Code]( https://baike.baidu.com/item/google Code / 2346604) and renamed MyBatis. Moved to in November 2013 Github. iBATIS comes from the combination of "internet" and "aba ...

1, JDBC specification 1.1 introduction to JDBC JDBC is the full name of Java Database Connectivity. Its original design intention is to provide a set of unified standards that can be applied to various databases. This set of standards needs to be observed by different database manufacturers, and provide their own implementation schemes for JD ...

Redis download and installation (Linux download) 1. Environmental preparation Virtual machine version: VMware ® Workstation 16 ProLinux system: Centos7Remote command side: xshellFile transfer tool: SecureFXPortable 2.Redis installation 2.1 Redis compilation language Redis is developed in C language. To install redis, you need to downl ...