主要涉及的内容：

• API开发框架 gin-gonic
• ORM框架 gorm
• Go语言 mysql 驱动

依赖包

框架引入 gin

$ go get github.com/gin-gonic/gin@latest
$ go get -u github.com/jinzhu/gorm@latest
$ go get github.com/go-sql-driver/mysql@latest

helloworld

package main
import "github.com/gin-gonic/gin"
func main() {
    r := gin.Default()
    r.GET("/ping", func(c *gin.Context) {
        c.JSON(200, gin.H{
            "message": "pong",
        })
    })
    // listen and serve on 0.0.0.0:8080
    r.Run()
}

路由设计

package main
import "github.com/gin-gonic/gin"
var router = gin.Default()
func init()  {
    router := gin.Default()
    v1 := router.Group("/api/v1/todos")
    {
        v1.POST("/", createTodo)
        v1.GET("/", fetchAllTodo)
        v1.GET("/:id", fetchSingleTodo)
        v1.PUT("/:id", updateTodo)
        v1.DELETE("/:id", deleteTodo)
    }
}

数据库设计

drop database if exists demo;
create database demo charset='utf8';
use demo;
drop table if exists todo;
create table todo (
    primary key(id),
    id int not null auto_increment,
    title varchar(256) not null default '待办事项',
    completed bool not null default 0,
    created_at timestamp not null default current_timestamp,
    updated_at timestamp not null default current_timestamp,
    deleted_at timestamp not null default current_timestamp
) Engine=Innodb;

连接数据库

package main
import (
    "github.com/jinzhu/gorm"
    _ "github.com/jinzhu/gorm/dialects/mysql"
)
var (
    db *gorm.DB
    sqlConnection = "golang:1234567890@(114.115.136.205)/demo?charset=utf8&parseTime=True&loc=Local"
)
func init() {
    //打开数据库连接
    var err error
    db, err = gorm.Open("mysql", sqlConnection)
    if err != nil {
        panic("failed to connect database")
    }
    db.AutoMigrate(&todoModel{})
}

模型设计

package main
import "github.com/jinzhu/gorm"
type (
    // entity类
    todoModel struct {
        gorm.Model
        Title     string `json:"title"`
        Completed int    `json:"completed"`
    }
    // response entity
    transformedTodo struct {
        ID        uint   `json:"id"`
        Title     string `json:"title"`
        Completed bool   `json:"completed"`
    }
)

CRUD

package main
import (
    "github.com/gin-gonic/gin"
    "strconv"
    "net/http"
)
// createTodo add a new todo
func createTodo(c *gin.Context) {
    completed, _ := strconv.Atoi(c.PostForm("completed"))
    todo := todoModel{Title: c.PostForm("title"), Completed: completed}
    db.Save(&todo)
    c.JSON(http.StatusCreated, gin.H{"status": http.StatusCreated, "message": "Todo item created successfully!", "resourceId": todo.ID})
}
// fetchAllTodo fetch all todos
func fetchAllTodo(c *gin.Context) {
    var todos []todoModel
    var _todos []transformedTodo
    db.Find(&todos)
    if len(todos) <= 0 {
        c.JSON(http.StatusNotFound, gin.H{"status": http.StatusNotFound, "message": "No todo found!"})
        return
    }
    //transforms the todos for building a good response
    for _, item := range todos {
        completed := false
        if item.Completed == 1 {
            completed = true
        } else {
            completed = false
        }
        _todos = append(_todos, transformedTodo{ID: item.ID, Title: item.Title, Completed: completed})
    }
    c.JSON(http.StatusOK, gin.H{"status": http.StatusOK, "data": _todos})
}
// fetchSingleTodo fetch a single todo
func fetchSingleTodo(c *gin.Context) {
    var todo todoModel
    todoID := c.Param("id")
    db.First(&todo, todoID)
    if todo.ID == 0 {
        c.JSON(http.StatusNotFound, gin.H{"status": http.StatusNotFound, "message": "No todo found!"})
        return
    }
    completed := false
    if todo.Completed == 1 {
        completed = true
    } else {
        completed = false
    }
    _todo := transformedTodo{ID: todo.ID, Title: todo.Title, Completed: completed}
    c.JSON(http.StatusOK, gin.H{"status": http.StatusOK, "data": _todo})
}
// updateTodo update a todo
func updateTodo(c *gin.Context) {
    var todo todoModel
    todoID := c.Param("id")
    db.First(&todo, todoID)
    if todo.ID == 0 {
        c.JSON(http.StatusNotFound, gin.H{"status": http.StatusNotFound, "message": "No todo found!"})
        return
    }
    db.Model(&todo).Update("title", c.PostForm("title"))
    completed, _ := strconv.Atoi(c.PostForm("completed"))
    db.Model(&todo).Update("completed", completed)
    c.JSON(http.StatusOK, gin.H{"status": http.StatusOK, "message": "Todo updated successfully!"})
}
// deleteTodo remove a todo
func deleteTodo(c *gin.Context) {
    var todo todoModel
    todoID := c.Param("id")
    db.First(&todo, todoID)
    if todo.ID == 0 {
        c.JSON(http.StatusNotFound, gin.H{"status": http.StatusNotFound, "message": "No todo found!"})
        return
    }
    db.Delete(&todo)
    c.JSON(http.StatusOK, gin.H{"status": http.StatusOK, "message": "Todo deleted successfully!"})
}

编译打包

将多个go文件打包为一个可执行文件

go build main.go router.go controller.go config.go model.go

如果把所有的代码放在一个文件里面，直接运行即可go build main.go。

单元测试（略）

运维上线

nohup ./main &