How to use MySQL and JavaScript to implement a simple data analysis function

How to use MySQL and JavaScript to implement a simple data analysis function

MySQL is a commonly used relational database management system, and JavaScript is a commonly used script language, using these two technologies together, we can implement a simple data analysis function. This article will introduce how to perform data query and analysis through MySQL and JavaScript, and provide relevant code examples.

1. Create a database

First we need to create a database and create a table in the database to store the data to be analyzed. Suppose the data we want to analyze is a student's grade table, which contains the student's name, subjects and grades. We can create this table through the following SQL statement:

CREATE DATABASE data_analysis;
USE data_analysis;

CREATE TABLE student_scores (
  id INT AUTO_INCREMENT PRIMARY KEY,
  name VARCHAR(50),
  subject VARCHAR(50),
  score INT
);

2. Insert data

Next we need to insert some data into the table for subsequent data query and analysis. We can insert data through the following SQL statement:

INSERT INTO student_scores (name, subject, score) VALUES ('John', 'Math', 80);
INSERT INTO student_scores (name, subject, score) VALUES ('John', 'English', 90);
INSERT INTO student_scores (name, subject, score) VALUES ('John', 'Science', 70);
INSERT INTO student_scores (name, subject, score) VALUES ('Alice', 'Math', 85);
INSERT INTO student_scores (name, subject, score) VALUES ('Alice', 'English', 95);
INSERT INTO student_scores (name, subject, score) VALUES ('Alice', 'Science', 75);
INSERT INTO student_scores (name, subject, score) VALUES ('Bob', 'Math', 75);
INSERT INTO student_scores (name, subject, score) VALUES ('Bob', 'English', 80);
INSERT INTO student_scores (name, subject, score) VALUES ('Bob', 'Science', 85);

3. Query data

Next we can use JavaScript to query and analyze data. First we need to introduce the MySQL JavaScript library into the HTML file, and then use the following JavaScript code to connect to the database and query the data:

// 引入MySQL的JavaScript库
const mysql = require('mysql');

// 创建一个连接对象
const connection = mysql.createConnection({
  host: 'localhost',
  user: 'root',
  password: 'password',
  database: 'data_analysis'
});

// 连接数据库
connection.connect();

// 查询数据
connection.query('SELECT * FROM student_scores', function (error, results, fields) {
  if (error) throw error;

  // 对查询结果进行分析
  // ...

  // 关闭数据库连接
  connection.end();
});

4. Data analysis

In the callback function of the data query , we can analyze the query results. The following is a simple example to calculate the average score of each student:

// 查询数据
connection.query('SELECT * FROM student_scores', function (error, results, fields) {
  if (error) throw error;

  // 计算每个学生的平均成绩
  const students = {};
  results.forEach(function (row) {
    if (!(row.name in students)) {
      students[row.name] = {
        total: 0,
        count: 0
      };
    }
    students[row.name].total += row.score;
    students[row.name].count++;
  });

  // 打印每个学生的平均成绩
  for (const name in students) {
    const average = students[name].total / students[name].count;
    console.log(`${name}: ${average}`);
  }

  // 关闭数据库连接
  connection.end();
});

Through the above code example, we can use MySQL and JavaScript to implement a simple data analysis function. Of course, actual data analysis is often much more complex and may require the use of more advanced statistical libraries or tools. But this example can serve as a starting point to help us understand how to use MySQL and JavaScript for data query and analysis. Hope this article is helpful to you!

The above is the detailed content of How to use MySQL and JavaScript to implement a simple data analysis function. For more information, please follow other related articles on the PHP Chinese website!