How to develop a simple file management system using MySQL and Go language

How to use MySQL and Go language to develop a simple file management system

In recent years, with the rapid development of cloud storage, file management systems have gained popularity in various fields. widely used. This article will introduce how to use MySQL database and Go language to develop a simple file management system, and help readers understand how to use these two tools to build an efficient file management system.

1. System requirements analysis

Before we start writing code, we first need to determine the system requirements. A simple file management system should have the following functions:

1. User registration and login: Users require registration and login functions for subsequent file operations.
2. File upload and download: Users can upload files to the system and download uploaded files.
3. File classification and tags: Users can add categories and tags to files to facilitate management and retrieval.
4. File permission management: The system should be able to set different users' access permissions to files to ensure file security.

2. Preparation work

Before starting development, we need to prepare the following work:

1. Install MySQL: First, you need to install the MySQL database and create A database is used to store information about users and files.
2. Install Go language: You need to install the development environment of Go language and make sure it can run normally.

3. Database design

In order to meet the needs of the system, we need to design database tables to store user and file information. The following is a simple data table design:

1. User table (User):

   • id: user ID, primary key
   • username: Username
   • password: Password

2. File table (File):

   • id: File ID, primary key
   • filename: file name
   • filepath: file path
   • filesize: file size
   • owner_id: owner ID, ID field of the associated user table
   • category：File classification
   • tags：File tag
   • create_time：Creation time
   • update_time：Update time

4. Code Implementation

Before starting to write code, we need to use the MySQL driver of Go language to connect to the database. Execute the following command in the command line to install the MySQL driver:

go get github.com/go-sql-driver/mysql

The following is a simple Go code example that demonstrates how to connect to a MySQL database and perform simple database operations:

package main

import (
    "database/sql"
    "fmt"

    _ "github.com/go-sql-driver/mysql"
)

// 数据库连接信息
const (
    DBUsername = "your_username"
    DBPassword = "your_password"
    DBHost     = "your_host"
    DBPort     = "your_port"
    DBName     = "your_database_name"
)

func main() {
    // 构建连接字符串
    connStr := fmt.Sprintf("%s:%s@tcp(%s:%s)/%s", DBUsername, DBPassword, DBHost, DBPort, DBName)

    // 连接数据库
    db, err := sql.Open("mysql", connStr)
    if err != nil {
        fmt.Println("Failed to connect to database:", err)
        return
    }
    defer db.Close()

    // 查询用户表
    rows, err := db.Query("SELECT id, username, password FROM User")
    if err != nil {
        fmt.Println("Failed to query user table:", err)
        return
    }
    defer rows.Close()

    // 遍历查询结果
    for rows.Next() {
        var id int
        var username, password string
        err := rows.Scan(&id, &username, &password)
        if err != nil {
            fmt.Println("Failed to scan user table:", err)
            return
        }
        fmt.Println(id, username, password)
    }
}

Above The code demonstrates how to connect to the MySQL database and query the data of the user table. Readers can expand it according to their own needs.

5. Implementing system functions

After completing the database connection and basic database operations, we can start to implement the functions of the file management system. The following is a simplified code example that shows how to implement the file upload and download functions:

package main

import (
    "database/sql"
    "fmt"
    "io"
    "net/http"
    "os"

    _ "github.com/go-sql-driver/mysql"
)

// 数据库连接信息
const (
    DBUsername = "your_username"
    DBPassword = "your_password"
    DBHost     = "your_host"
    DBPort     = "your_port"
    DBName     = "your_database_name"
)

func main() {
    // 构建连接字符串
    connStr := fmt.Sprintf("%s:%s@tcp(%s:%s)/%s", DBUsername, DBPassword, DBHost, DBPort, DBName)

    // 连接数据库
    db, err := sql.Open("mysql", connStr)
    if err != nil {
        fmt.Println("Failed to connect to database:", err)
        return
    }
    defer db.Close()

    // 上传文件接口
    http.HandleFunc("/upload", func(w http.ResponseWriter, r *http.Request) {
        // 解析文件
        file, header, err := r.FormFile("file")
        if err != nil {
            fmt.Println("Failed to parse file:", err)
            return
        }
        defer file.Close()

        // 创建文件
        dst, err := os.Create("/path/to/save/" + header.Filename)
        if err != nil {
            fmt.Println("Failed to create file:", err)
            return
        }
        defer dst.Close()

        // 复制文件
        _, err = io.Copy(dst, file)
        if err != nil {
            fmt.Println("Failed to copy file:", err)
            return
        }

        // 插入文件表
        _, err = db.Exec("INSERT INTO File (filename, filepath) VALUES (?, ?)", header.Filename, dst.Name())
        if err != nil {
            fmt.Println("Failed to insert into file table:", err)
            return
        }

        fmt.Fprintln(w, "File uploaded successfully!")
    })

    // 下载文件接口
    http.HandleFunc("/download", func(w http.ResponseWriter, r *http.Request) {
        filename := r.URL.Query().Get("filename")

        // 查询文件路径
        var filepath string
        err := db.QueryRow("SELECT filepath FROM File WHERE filename = ?", filename).Scan(&filepath)
        if err != nil {
            fmt.Println("Failed to query file table:", err)
            return
        }

        // 打开文件
        file, err := os.Open(filepath)
        if err != nil {
            fmt.Println("Failed to open file:", err)
            return
        }
        defer file.Close()

        // 设置响应头
        w.Header().Set("Content-Disposition", fmt.Sprintf("attachment; filename=%s", filename))
        w.Header().Set("Content-Type", "application/octet-stream")

        // 写入文件内容
        _, err = io.Copy(w, file)
        if err != nil {
            fmt.Println("Failed to write file:", err)
            return
        }
    })

    // 启动HTTP服务器
    fmt.Println("Server started on http://localhost:8080")
    http.ListenAndServe(":8080", nil)
}

The above code demonstrates how to implement the file upload and download functions. Readers can expand and improve other system functions according to their own needs.

6. Summary

Through the method introduced in this article, we can develop a simple file management system using MySQL database and Go language. Through reasonable database design and code implementation, we can easily manage and operate files, improving work efficiency and data security. I hope this article will be helpful to readers and further improve everyone’s development capabilities.

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