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mysql login mysql -uroot -p password mysql -hip -uroot -p Password for connection target mysql --host=ip --user=root --password=Password for connection target MySQL exit exit quit DDL: operation database and table Create database create database Database name; Create a database, judge that it does not exist, a ...

1, Restraint· 1. Primary key constraint We can add constraints to a data table of a data table so that it can uniquely identify a data table. After being constrained, the data is not repeated and not unique: primary key mysql> use test; mysql> create table number( -> id int primary key, -> name varchar(20) -> ...

1 Introduction to MySQL database MySQL is a relational database. Due to its small size, fast speed, low total cost of ownership and open source, many small and medium-sized websites choose MySQL as the website database in order to reduce the total cost of ownership. Other advantages: it can be combined with other development languages, por ...

MyBatis if is similar to the if statement in Java. It is the most commonly used judgment statement in MyBatis. Using the if tag can save a lot of work in splicing SQL and focus on the maintenance of XML. The if statement is simple to use and is often used in combination with the test attribute. The syntax is as follows. When the judgment con ...

1.PHP: php installation:     Install - double click exe  —— Find the installed folder - double click the executable exe - click start 1. Double click exe:   2. After installation, execute exe and click Start: 3. When the status is green, the installation is successful:     php application: How to acces ...

1, Mysql database 1. What are sql, DB and DBMS, and the relationship between them? DB: database (database, which actually exists as a file on the hard disk)DBMS: database management system (database management system, including Mysql, Oracle and DB2)SQL: structured query language, a standardized general language. Standard SQL is suitable for ...

MySql logical architecture It is mainly divided into: connection layer, service layer, engine layer and storage layer. The process of the client executing a select command is as follows: Connection layer: the top layer is some clients and connection services, including local sock communication and most communication similar to tcplip b ...

Database notes 01 introduction to MySQL and SQL statements (Part I) 1, Server, database introduction: The server: Concept: a computer that can provide a service. A server is a combination of hardware and softwareDatabase server: a computer equipped with database software, which can provide data addition, deletion, modification and query ...

Distributed data storage solution for 100 million users 1 1. Introduction MySQL Cluster is a high-performance, scalable and clustered database product. Its original intention of R & D and design is to meet the most severe application requirements in many industries. In these applications, the reliability of database operation is often ...

1, Canal introduction In the early days, Alibaba had the business requirement of cross machine room synchronization due to the deployment of dual machine rooms in Hangzhou and the United States. The implementation method was mainly to obtain incremental changes based on the business trigger. Since 2010, the business has gradually tried to obta ...