How to install database using PHP commands

PHP is a widely used open source scripting language that can be directly embedded in HTML and is suitable for Web development. In web development, PHP can be used to quickly connect to the database and realize online data processing. The following will introduce in detail how to install the database using PHP commands.

1. Related environment preparation

Before starting to install the database, make sure you have correctly installed PHP and MySQL databases. Additionally, make sure you have added PHP and MySQL to your environment variables.

2. PHP command to connect to MySQL

Before installing the database, you need to use the PHP command to connect to MySQL to verify whether PHP can successfully connect to the MySQL database. In Linux, you can enter the following command in the terminal to check whether the connection is successful.

php -r 'echo "Hello, World!" . PHP_EOL;'

This command creates a simple output statement in PHP that outputs "Hello, World!" and breaks the line. If the terminal successfully outputs "Hello, World!", it means that the PHP environment and PHP commands have been installed correctly.

3. Create database

When using PHP commands to create a database, you need to use the MySQL command line tool to complete it. In Linux, you can enter the following command in the terminal to log in to MySQL (you need to enter the MySQL user name and password):

mysql -u root -p

After entering the correct user name and password, enter the MySQL command line interface. Next, enter the following command to create a database named "test".

CREATE DATABASE test;

After executing the above command, check whether the database named "test" is successfully created in the MySQL database.

4. Create or delete a database table

When creating or deleting a database table, you first need to select a default database. In the MySQL command line interface, you can use the "use" command to switch databases, as shown below.

use test;

After entering the above command, switch to the test database. Next, you can use the following command to create a database table.

CREATE TABLE `user` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) DEFAULT NULL,
  `email` varchar(255) DEFAULT NULL,
  `age` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

The above command is used to create a database table named "user". The table contains four columns, namely id, name, email and age. Among them, the id column is a self-increasing column, which represents the primary key and cannot be repeated. Other columns can be empty.

If you need to delete this table, you can use the following command to operate.

DROP TABLE user;

The above command is used to delete the table user. Please be careful when doing this, because this operation will delete all the data in the table and cannot be restored.

5. Insert, modify and delete data

If you need to insert data into the database, you can use the following commands.

INSERT INTO user (name, email, age) VALUES ('张三', 'zhangsan@example.com', 20);

The above command is used to insert a piece of data into the user table, where name, email, and age are the corresponding columns, and the corresponding values ​​need to be added to VALUES.

If you need to modify the data in this table, you can use the following command.

UPDATE user SET age=30 WHERE name='张三';

The above command is used to modify the age of "Zhang San" to 30.

If you need to delete the data in this table, you can use the following command.

DELETE FROM user WHERE name='张三' AND age=30;

The above command will delete the record named "Zhang San" with an age equal to 30.

6. Summary

It is very simple to install a database using PHP commands. You only need to master the basic MySQL commands to quickly create a database and perform data operations. Of course, in actual development, PHP has many other features and techniques for connecting to MySQL, which need to be accumulated through continuous practice.

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