go env -w GO111MODULE=on

go mod init test003

go get -u github.com/gin-gonic/gin

package main

import "github.com/gin-gonic/gin"

func main() {
	router := gin.Default()
	router.GET("/", func(c *gin.Context) {
		c.JSON(200, gin.H{
			"message": "hello world",
		})
	})
	router.Run()
}

@zq2599 ? /workspaces/blog_demos/tutorials/test003 (dev) $ go run main.go
[GIN-debug] [WARNING] Creating an Engine instance with the Logger and Recovery middleware already attached.

[GIN-debug] [WARNING] Running in "debug" mode. Switch to "release" mode in production.
 - using env:   export GIN_MODE=release
 - using code:  gin.SetMode(gin.ReleaseMode)

[GIN-debug] GET    /                         --> main.main.func1 (3 handlers)
[GIN-debug] [WARNING] You trusted all proxies, this is NOT safe. We recommend you to set a value.
Please check https://pkg.go.dev/github.com/gin-gonic/gin#readme-don-t-trust-all-proxies for details.
[GIN-debug] Environment variable PORT is undefined. Using port :8080 by default
[GIN-debug] Listening and serving HTTP on :8080
[GIN] 2023/02/04 - 14:10:22 | 200 |        58.7μs | 220.246.254.226 | GET      "/"
[GIN] 2023/02/04 - 14:10:22 | 404 |         900ns | 220.246.254.226 | GET      "/favicon.ico"

docker run \
--name mysql \
-p 3306:3306 \
-e MYSQL_ROOT_PASSWORD=123456 \
-d \
mariadb:10.3

docker exec -it mysql /bin/bash

mysql -uroot -p123456

create database demo;
use demo;

go get -u gorm.io/gorm
go get -u gorm.io/driver/mysql

package main

import (
	"fmt"
	"strconv"

	"github.com/gin-gonic/gin"
	"gorm.io/driver/mysql"
	"gorm.io/gorm"
)

type Student struct {
	gorm.Model
	Name string
	Age  uint64
}

// 全局數(shù)據(jù)庫 db
var db *gorm.DB

// 包初始化函數(shù)，可以用來初始化 gorm
func init() {
	// 賬號
	username := "root"
	// 密碼
	password := "123456"
	// mysql 服務地址
	host := "127.0.0.1"
	// 端口
	port := 3306
	// 數(shù)據(jù)庫名
	Dbname := "demo"

	// 拼接 mysql dsn，即拼接數(shù)據(jù)源，下方 {} 中的替換參數(shù)即可
	// {username}:{password}@tcp({host}:{port})/{Dbname}?charset=utf8&parseTime=True&loc=Local&timeout=10s&readTimeout=30s&writeTimeout=60s
	// timeout 是連接超時時間，readTimeout 是讀超時時間，writeTimeout 是寫超時時間，可以不填
	dsn := fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?charset=utf8&parseTime=True&loc=Local", username, password, host, port, Dbname)

	// err
	var err error
	// 連接 mysql 獲取 db 實例
	db, err = gorm.Open(mysql.Open(dsn), &gorm.Config{})
	if err != nil {
		panic("連接數(shù)據(jù)庫失敗, error=" + err.Error())
	}

	// 設置數(shù)據(jù)庫連接池參數(shù)
	sqlDB, _ := db.DB()
	// 設置數(shù)據(jù)庫連接池最大連接數(shù)
	sqlDB.SetMaxOpenConns(10)
	// 連接池最大允許的空閑連接數(shù)，如果沒有sql任務需要執(zhí)行的連接數(shù)大于2，超過的連接會被連接池關閉
	sqlDB.SetMaxIdleConns(2)

	// 建表
	db.AutoMigrate(&Student{})
}

func main() {

	router := gin.Default()
	router.GET("/", func(c *gin.Context) {
		c.JSON(200, gin.H{
			"message": "hello world",
		})
	})

	router.GET("/create", func(c *gin.Context) {
		name := c.DefaultQuery("name", "小王子")
		ageStr := c.DefaultQuery("age", "1")

		var age uint64
		var err error
		if age, err = strconv.ParseUint(ageStr, 10, 32); err != nil {
			age = 1
		}

		fmt.Printf("name [%v], age [%v]\n", name, age)

		student := &Student{
			Name: name,
			Age:  age,
		}

		if err := db.Create(student).Error; err != nil {
			c.JSON(500, gin.H{
				"code":    0,
				"message": "insert db error",
			})

			return
		}

		c.JSON(200, gin.H{
			"code":    0,
			"message": fmt.Sprintf("insert db success [%+v]", student.Model.ID),
		})

	})
	router.Run()
}

root@5e9f15ab9ac1:/# mysql -uroot -p123456
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MariaDB connection id is 42
Server version: 10.3.37-MariaDB-1:10.3.37+maria~ubu2004 mariadb.org binary distribution

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [(none)]> use demo;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
MariaDB [demo]> select * from students;
+----+-------------------------+-------------------------+------------+------+------+
| id | created_at              | updated_at              | deleted_at | name | age  |
+----+-------------------------+-------------------------+------------+------+------+
|  1 | 2023-02-05 02:05:56.733 | 2023-02-05 02:05:56.733 | NULL       | Tom  |   10 |
|  2 | 2023-02-05 02:09:35.537 | 2023-02-05 02:09:35.537 | NULL       | Tom  |   10 |
|  3 | 2023-02-05 02:10:43.815 | 2023-02-05 02:10:43.815 | NULL       | Tom  |   10 |
|  4 | 2023-02-05 02:10:45.069 | 2023-02-05 02:10:45.069 | NULL       | Tom  |   10 |
|  5 | 2023-02-05 02:10:45.717 | 2023-02-05 02:10:45.717 | NULL       | Tom  |   10 |
|  6 | 2023-02-05 02:10:46.000 | 2023-02-05 02:10:46.000 | NULL       | Tom  |   10 |
|  7 | 2023-02-05 02:10:46.213 | 2023-02-05 02:10:46.213 | NULL       | Tom  |   10 |
|  8 | 2023-02-05 02:10:46.578 | 2023-02-05 02:10:46.578 | NULL       | Tom  |   10 |
|  9 | 2023-02-05 02:10:46.780 | 2023-02-05 02:10:46.780 | NULL       | Tom  |   10 |
| 10 | 2023-02-05 02:10:46.976 | 2023-02-05 02:10:46.976 | NULL       | Tom  |   10 |
| 11 | 2023-02-05 02:10:47.155 | 2023-02-05 02:10:47.155 | NULL       | Tom  |   10 |
| 12 | 2023-02-05 02:10:47.359 | 2023-02-05 02:10:47.359 | NULL       | Tom  |   10 |
+----+-------------------------+-------------------------+------------+------+------+
12 rows in set (0.000 sec)