Golang Gin 项目代码结构之共享 MySQL 数据库连接

Gin 项目代码目录结构

新建 models 目录，用于管理 Golang Gin 项目的数据库相关的操作，同时定义一批 model，即 struct。

> mkdir models
> touch models/kv.go
> touch models/db.go
> tree
.
├── controllers
│   └── hello.go
├── go.mod
├── go.sum
├── main.go
├── models
│   ├── db.go
│   └── kv.go
├── public
│   └── js
│       └── main.min.js
└── views
    └── hello.html

5 directories, 8 files

models/db.go

package models

import (
	"database/sql"
	_ "github.com/go-sql-driver/mysql"
	"log"
)

var db *sql.DB

func InitDB(dataSourceName string) {
	var err error
	db, err = sql.Open("mysql", dataSourceName)

	if err != nil {
		log.Fatal("Error")
	}

	//defer db.Close()
}

models/kv.go 一个 model 样例

package models

type KV struct {
	Id         int
	Key        string
	Value      string
	Updated_at string
}

func GetValue(key string) (*KV, error) {
	var kv KV
	err := db.QueryRow("SELECT id, `key`, value, updated_at FROM kv where id = ?",
		key).Scan(&kv.Id, &kv.Key, &kv.Value, &kv.Updated_at)
	if err != nil {
		panic(err.Error()) // proper error handling instead of panic in your app
	}

	db.Exec(`update kv 
		set value = value + 1, updated_at = now() 
		where id = ?`, key)

	return &kv, err
}

main.go 中初始化 MySQL 数据库连接

package main

import (
	"fmt"
	"github.com/gin-gonic/gin"
	"github.com/joho/godotenv"
	"log"
	"os"
	"sunzhongwei.com/go_tool/controllers"
	"sunzhongwei.com/go_tool/models"
)

func main() {
	err := godotenv.Load("../.env")
	if err != nil {
		log.Fatal("Error loading .env file")
	}
	db_database := os.Getenv("DB_DATABASE")
	db_username := os.Getenv("DB_USERNAME")
	db_password := os.Getenv("DB_PASSWORD")
	db_host := os.Getenv("DB_HOST")
	db_port := os.Getenv("DB_PORT")
	models.InitDB(fmt.Sprintf("%s:%s@tcp(%s:%s)/%s?charset=utf8mb4&timeout=5000ms",
		db_username, db_password, db_host, db_port, db_database))

	router := gin.Default()
	router.LoadHTMLGlob("views/*.html")
	router.Static("/go/public", "./public")
	router.GET("/hello", controllers.HelloIndex)
	router.Run() // listen and serve on 0.0.0.0:8080
}

controllers/hello.go 中访问 model

package controllers

import (
	"github.com/gin-gonic/gin"
	"net/http"
	"sunzhongwei.com/go_tool/models"
)

func HelloIndex(c *gin.Context) {
	models.GetValue("2")
	c.HTML(http.StatusOK, "hello.html", gin.H{})
}

转载

https://www.sunzhongwei.com/golang-gin-mysql-database-connection-sharing-of-project-code-structure?from=sidebar_new