- ISBN: 7115322473, 9787115322470
- 示例代码
3.3.6
高效的轻量级第三方多路复用器:HttpRouter
6.3 Go与SQL
修改postgres数据库的用户密码
ALTER USER gwp WITH PASSWORD 'gwp';
使用MySQL(原书使用的是PostgreSQL)
1. 下载驱动 go get github.com/go-sql-driver/mysql
import "database/sql"
import _ "github.com/go-sql-driver/mysql"
// A DSN in its fullest form
username:password@protocol(address)/dbname?param=value
db, err := sql.Open("mysql", "root:root@tcp(127.0.0.1:3306)/gwp?charset=utf8")
2. 创建表
CREATE TABLE `posts` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`content` varchar(1000) CHARACTER SET utf8 DEFAULT NULL,
`author` varchar(200) CHARACTER SET utf8 DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='帖子'
3. mysql_store.go
package main
import (
"database/sql"
_ "github.com/go-sql-driver/mysql"
"fmt"
"log"
)
type Post struct {
Id int
Content string
Author string
}
var Db *sql.DB
// connect to the Db
func init() {
var err error
Db, err = sql.Open("mysql", "root:root@tcp(127.0.0.1:3306)/gwp?charset=utf8")
if err != nil {
panic(err)
}
}
// get all posts
func Posts(start int, size int) (posts []Post, err error) {
rows, err := Db.Query("select id, content, author from posts limit ?, ?", start, size)
defer rows.Close()
if err != nil {
return
}
for rows.Next() {
post := Post{}
err = rows.Scan(&post.Id, &post.Content, &post.Author)
if err != nil {
return
}
posts = append(posts, post)
}
return
}
// Get a single post
func GetPost(id int64) (post Post, err error) {
post = Post{}
err = Db.QueryRow("select id, content, author from posts where id = ?", id).Scan(&post.Id, &post.Content, &post.Author)
return
}
// Create a new post
func (post *Post) Create() (id int64, err error) {
statement := "insert into posts (content, author) values (?, ?)"
stmt, err := Db.Prepare(statement)
if err != nil {
return
}
//res, err := stmt.Exec(post.Content, post.Author)
res, err := stmt.Exec("李雷爱吃雪糕", "李雷")
defer stmt.Close()
id, err = res.LastInsertId()
return
}
// Update a post
func (post *Post) Update() (err error) {
_, err = Db.Exec("update posts set content = ?, author = ? where id = ?", post.Content, post.Author, post.Id)
return
}
// Delete a post
func (post *Post) Delete() (err error) {
_, err = Db.Exec("delete from posts where id = ?", post.Id)
return
}
// Delete all posts
func DeleteAll() (err error) {
_, err = Db.Exec("delete from posts")
return
}
func main() {
post := Post{Content: "李雷和韩梅梅", Author: "李雷"}
// Create a post
fmt.Println("准备添加:", post) // {0 Hello World! Sau Sheong}
id, err := post.Create()
if err != nil {
log.Fatalln(err)
}
// Get one post
readPost, _ := GetPost(id)
fmt.Println("根据id获得帖子:", readPost) // {1 Hello World! Sau Sheong}
// Update the post
readPost.Content = "Bonjour Monde!"
readPost.Author = "Pierre"
readPost.Update()
posts, _ := Posts(0, 10)
fmt.Println(posts)
/*// Get all posts
posts, _ := Posts(10)
fmt.Println(posts)
// Delete the post
readPost.Delete()
// Get all posts
posts, _ = Posts(10)
fmt.Println(posts) // []*/
// Delete all posts
// DeleteAll()
}
6.5 Go与关系映射器
- Gorm
- Beego的ORM库以及GORP
- 如果写web程序的话 用 go-macaron(朋友推荐)
- Gogs使用go-macaron开发
7.1 Web服务简介
- REST 速度快并且构建简单;数据驱动。
- SOAP 安全并且健壮;功能驱动;不仅笨重,而且过于复杂。
7.3 基于REST的Web服务简介
- WADL、Swagger、RAML(Restful API Modeling Language,REST风格API建模语言)、JSON-home。
7.5.1 分析JSON
- 如果JSON数据来源于io.Reader流,如http.Request的Body,那么使用Decoder更好;
- 如果JSON数据来源于字符串或者内存的某个地方,那么使用Unmarshal更好。
8.2 使用Go进行单元测试
- 使用具体(verbose)标识-v来获得更详细的信息,并通过覆盖率标识-cover来获知测试用例对代码的覆盖率
go test -v -cover
8.2.1 跳过测试用例
// Long running test case
func TestLongRunningTest(t *testing.T) {
if testing.Short() {
t.Skip("Skipping long running test in short mode")
}
time.Sleep(10 * time.Second)
}
go test -short
8.2.2 以并行方式运行测试
parallel_test.go
package main
import (
"testing"
"time"
)
func TestParallel_1(t *testing.T) {
t.Parallel()
time.Sleep(1 * time.Second)
}
func TestParallel_2(t *testing.T) {
t.Parallel()
time.Sleep(2 * time.Second)
}
func TestParallel_3(t *testing.T) {
t.Parallel()
time.Sleep(3 * time.Second)
}
go test -parallel 3
8.2.3 基准测试
基准测试用例也需要放置到以_test.go为后缀的文件中,并且每个基准测试函数都需要符合以下格式
func BenchmarkXxx(*testing.B) {...}
package main
import (
"testing"
)
func BenchmarkDecode(b *testing.B) {
for i := 0; i < b.N; i++ {
decode("post.json")
}
}
func BenchmarkUnmarshal(b *testing.B) {
for i := 0; i < b.N; i++ {
unmarshal("post.json")
}
}
// -bench后使用一个正则表达式用作该标志的参数,从而标识出自己想要运行的基准测试文件。
// 当我们需要运行目录下的所有基准测试文件是,只需要把.用作-bench标志的参数即可
go test -v -cover -short -bench .
// 用户可以通过-run来忽略功能测试
// -run标志用于指定需要被执行的功能测试用例,如果用户把一个不存在的功能测试名字用作-run标志的参数,
// 那么所有功能测试都将被忽略。
// x是不存在的功能测试用例
go test -run x -bench .
8.5 第三方Go测试库
- Gocheck较为简单,整合并扩展了testing包;
- Ginkgo能够让用户在Go中实现行为驱动开发,但是这个库比较复杂,而且学习曲线也比较陡峭。