How to use Mysql to manage relational databases

MySQL is a popular open source relational database management system that is widely used for data management on websites and applications. If you are a beginner and want to know how to use MySQL to manage a relational database, then this article will introduce you to the basic usage of MySQL.

The first step is to install MySQL

Before using MySQL, you need to install MySQL first. You can download the MySQL installation program from the official MySQL website https://dev.mysql.com/downloads/mysql/ and follow the prompts to complete the installation process. During the installation process, you can set the root user password and port and other related information.

Second step, connect to MySQL

After the installation is complete, you can use the client program provided by MySQL to connect to the MySQL server. There are many different clients to choose from, such as MySQL Workbench, Navicat or command line. This article uses the command line method as an example. Enter the following command on the command line to connect to the MySQL server:

mysql -u root -p

The -u parameter is used to specify the user name for the connection, and the -p parameter is used to prompt for a password. If you set a port number, you can use the -h parameter to specify the server's address and port.

The third step, manage the MySQL server

After the connection is successful, you can start to manage the MySQL server, including creating, modifying and deleting databases, as well as adding, modifying and deleting tables.

1. Create database

On the MySQL server, you can use the CREATE DATABASE statement to create a new database. For example, the following command will create a database named mydatabase:

CREATE DATABASE mydatabase;

2. Using the database

To use the database you have created, you need to use the USE statement. For example, the following command will use the database named mydatabase:

USE mydatabase;

3. Create table

On a MySQL server, you can use the CREATE TABLE statement to create a new table. For example, the following command will create a table named mytable:

CREATE TABLE mytable (
id INT(11) NOT NULL AUTO_INCREMENT,
name VARCHAR(255) NOT NULL,
age INT(11) NOT NULL,
PRIMARY KEY (id)
);

This command creates a table named mytable and defines columns such as id, name and age, where the id column is auto-incrementing and as Primary key.

4. Insert data

On the MySQL server, you can use the INSERT INTO statement to insert data into the table. For example, the following command will insert a record into the mytable table:

INSERT INTO mytable (name, age) VALUES ('Tom', 20);

5. Query data

On the MySQL server, you can use the SELECT statement to query the data in the table . For example, the following command will return all records in the mytable table:

SELECT * FROM mytable;

6. Modify data

On the MySQL server, you can use the UPDATE statement to modify the data in the table. For example, the following command will change the name of the record with age 20 in the mytable table to Jerry:

UPDATE mytable SET name='Jerry' WHERE age=20;

7. Delete data

On the MySQL server, you can use DELETE statement to delete data from the table. For example, the following command will delete records with an age of 20 in the mytable table:

DELETE FROM mytable WHERE age=20;

8. Delete table and database

On the MySQL server, you can use the DROP TABLE statement to Delete the table. For example, the following command will delete the table named mytable:

DROP TABLE mytable;

On a MySQL server, you can use the DROP DATABASE statement to drop a database. For example, the following command will delete the database named mydatabase:

DROP DATABASE mydatabase;

Summary

MySQL is a very powerful relational database management system that supports a variety of operations and query languages. When using MySQL, pay attention to correct syntax and operating specifications to avoid possible errors and vulnerabilities. Through this article, I hope you have a certain understanding of MySQL and can further learn its more advanced usage.

The above is the detailed content of How to use Mysql to manage relational databases. For more information, please follow other related articles on the PHP Chinese website!