Go 数据库

Golang之redis

redis是个开源的高性能的key-value的内存数据库，可以把它当成远程的数据结构。
支持的value类型非常多，比如string、list（链表）、set（集合）、
hash表等等
redis性能非常高，单机能够达到15w qps，通常适合做缓存。

使用第三方开源的redis库: github.com/garyburd/redigo/redis
import(
 "github.com/garyburd/redigo/redis"
）

1、windows安装redis

下载安装
https://github.com/MicrosoftArchive/redis 

解压，启动，如下

1

2、linxu安装redis

https://redis.io/download

3、连接redis

package main

import (
    "fmt"
    "github.com/garyburd/redigo/redis"
)
func main(){
    c,err:=redis.Dial("tcp","127.0.0.1:6379")
    if err!=nil{
        fmt.Println("conn redis failed,",err)
        return
    }
    //fmt.Println("连接成功",c)
    defer c.Close()
}

4、set，get，设置键值，取得键值

package main

import (
    "fmt"
    "github.com/garyburd/redigo/redis"
)

func main() {
    //p是指针类型int
    var p *int
    var a int
    p = &a //p变量是个指针，指向a的内存地址
    *p = 0
    c, err := redis.Dial("tcp", "localhost:6379")
    if err != nil {
        //错误处理
        fmt.Println("conn redis failed,", err)
        return
    }
    defer c.Close()
    //设置值
    _, err = c.Do("Set", "abc", 100)
    if err != nil {
        fmt.Println(err)
        return
    }
    //从redis取值，取int类型的值
    r, err := redis.Int(c.Do("Get", "abc"))
    if err != nil {
        fmt.Println("get abc failed,", err)
        return
    }
    fmt.Println(r)
    //从redis取值，取name，string类型的值
    r1, err := redis.String(c.Do("Get", "name"))
    if err != nil {
        fmt.Println("get abc failed,", err)
        return
    }
    fmt.Println(r1)

}

5、hash表设置键值，取键值

package main

import (
    "fmt"
    "github.com/garyburd/redigo/redis"
)

func main() {
    c, err := redis.Dial("tcp", "127.0.0.1:6379")
    if err != nil {
        fmt.Println("conn redis failed,", err)
        return
    }
    defer c.Close()
    //设置hash
    _, err = c.Do("HSet", "books", "abc", 100)
    if err != nil {
        fmt.Println(err)
        return
    }
    //取得hash
    r, err := redis.Int(c.Do("HGet", "books", "abc"))
    if err != nil {
        fmt.Println("get abc failed,", err)
        return
    }
    fmt.Println(r)


}

6、批量set键值

package main

import (
    "fmt"
    "github.com/garyburd/redigo/redis"
)

func main() {
    //建立连接
    c, err := redis.Dial("tcp", "127.0.0.1:6379")
    if err != nil {
        fmt.Println("conn redis failed,", err)
        return
    }
    defer c.Close()
    _, err = c.Do("MSet", "abc", 100, "efg", 300)
    if err != nil {
        fmt.Println(err)
        return
    }
    r, err := redis.Ints(c.Do("MGet", "abc", "efg"))
    if err != nil {
        fmt.Println("get abc failed,", err)
        return
    }
    for _, v := range r {
        fmt.Println(v)
    }
}

7、设置过期时间

package main

import (
    "fmt"

    "github.com/garyburd/redigo/redis"
)

func main() {
    c, err := redis.Dial("tcp", "127.0.0.1:6379")
    if err != nil {
        fmt.Println("conn redis failed,", err)
    }
    defer c.Close()
    _, err = c.Do("expire", "abc", 10)
    if err != nil {
        fmt.Println(err)
        return
    }
}

8.list队列操作

package main

import (
    "fmt"
    "github.com/garyburd/redigo/redis"
)

func main() {
    c, err := redis.Dial("tcp", "127.0.0.1:6379")
    if err != nil {
        fmt.Println("conn redis failed,", err)
        return
    }
    defer c.Close()
    _, err = c.Do("lpush", "book_list", "abc", "efg", 300)
    if err != nil {
        fmt.Println(err)
        return
    }
    r, err := redis.String(c.Do("lpop", "book_list"))
    if err != nil {
        fmt.Println("get abc failed,", err)
        return
    }
    fmt.Println(r)
}

9、redis连接池pool

package main

import (
    "fmt"
    "github.com/garyburd/redigo/redis"
)

//poll是指针
var pool *redis.Pool

//初始化执行函数
func init() {
    pool = &redis.Pool{
        MaxIdle:     16,
        MaxActive:   0,
        IdleTimeout: 300,
        Dial: func() (redis.Conn, error) {
            return redis.Dial("tcp", "127.0.0.1:6379")
        },
    }
}
func main() {
    c := pool.Get()
    defer c.Close()
    _, err := c.Do("Set", "abc", 100)
    if err != nil {
        fmt.Println(err)
        return
    }
    r, err := redis.Int(c.Do("Get", "abc"))
    if err != nil {
        fmt.Println("get abc failed,", err)
        return
    }
    fmt.Println(r)
    pool.Close()
}

Golang之Mysql操作

增加insert

package main

import (
    "fmt"
    "github.com/jmoiron/sqlx"
    _ "github.com/go-sql-driver/mysql" //初始化一个mysql驱动，必须
)

type Person struct {
    UserId   int    `db:"user_id"`
    Username string `db:"username"`
    Sex      string `db:"sex"`
    Email    string `db:"email"`
}
type Place struct {
    Country string `db:"country"`
    City    string `db:"city"`
    TelCode int    `db:"telcode"`
}

var Db *sqlx.DB

func init() {
    //"mysql"指定数据库类型，  /test指定数据库  root:123 冒号隔开密码 root账号 123密码
    database, err := sqlx.Open("mysql", "root@tcp(127.0.0.1:3306)/test")
    if err != nil {
        fmt.Println("open mysql failed,", err)
        return
    }
    Db = database
}
func main() {
    //插入数据入表
    r, err := Db.Exec("insert into person(username,sex,email)values(?,?,?)", "chaoge", "man", "yc_uuu@163.com")
    if err != nil {
        fmt.Println("exec failed,", err)
        return
    }
    id, err := r.LastInsertId()
    if err != nil {
        fmt.Println("exec failed,", err)
        return
    }
    fmt.Println("insert succ:", id)
}

查询select

package main

import (
    "fmt"
    _ "github.com/go-sql-driver/mysql"
    "github.com/jmoiron/sqlx"
)

type Person struct {
    UserId   int    `db:"user_id"'`
    Username string `db:"username"`
    Sex      string `db:"sex"`
    Email    string `db:"email"`
}
type Place struct {
    Country string `db:"country"`
    City    string `db:"city"`
    TelCode int    `db:"telcode"`
}

var Db *sqlx.DB

func init() {
    //初始化链接数据库
    database, err := sqlx.Open("mysql", "root:@tcp(127.0.0.1:3306)/test")
    if err != nil {
        fmt.Println("open mysql failed", err)
        return
    }
    Db = database
}

func main() {
    var person []Person
    err := Db.Select(&person, "select user_id,username,sex,email from person where user_id=?", 1)
    if err != nil {
        fmt.Println("exec failed,", err)
        return
    }
    fmt.Println("select succ:", person)

}

改update

package main

import (
    "fmt"
    _ "github.com/go-sql-driver/mysql"
    "github.com/jmoiron/sqlx"
)

type Person struct {
    UserId   int    `db:"user_id"`
    Username string `db:"username"`
    Sex      string `db:"sex"`
    Email    string `db:"email"`
}
type Place struct {
    Country string `db:"country"`
    City    string `db:"city"`
    TelCode int    `db:"telcode"`
}

var Db *sqlx.DB

func init() {
    database, err := sqlx.Open("mysql", "root@tcp(127.0.0.1:3306)/test")
    if err != nil {
        fmt.Println("open mysql failed,", err)
        return
    }
    Db = database
}
func main() {
    _, err := Db.Exec("update person set username=? where user_id=?", "chaoge666", 1)
    if err != nil {
        fmt.Println("exec failed,", err)
    }
}

删delete

package main

import (
    "fmt"
    _ "github.com/go-sql-driver/mysql"
    "github.com/jmoiron/sqlx"
)

type Person struct {
    UserId   int    `db:"user_id"`
    Username string `db:"username"`
    Sex      string `db:"sex"`
    Email    string `db:"email"`
}

type Place struct {
    Country string `db:"country"`
    City    string `db:"city"`
    TelCode int    `db:"telcode"`
}

var Db *sqlx.DB

func init() {
    //初始化链接数据库
    database, err := sqlx.Open("mysql", "root@tcp(127.0.0.1:3306)/test")
    if err != nil {
        fmt.Println("open mysql failed,", err)
        return
    }
    Db = database
}

func main() {
    _, err := Db.Exec("delete FROM person where user_id=?", 1)
    if err != nil {
        fmt.Println("exec failed,", err)
        return
    }
    fmt.Println("delete succ")
}

Golang之Mysql事务

Mysql事务
1)原子性
2)一致性
3)隔离性
4)持久性

示例代码

package main

import (
    "fmt"
    _ "github.com/go-sql-driver/mysql" //初始化一个mysql驱动，必须
    "github.com/jmoiron/sqlx"
)

type Person struct {
    UserId   int    `db:"user_id"`
    Username string `db:"username"`
    Sex      string `db:"sex"`
    Email    string `db:"email"`
}
type Place struct {
    Country string `db:"country"`
    City    string `db:"city"`
    TelCode int    `db:"telcode"`
}

var Db *sqlx.DB

func init() {
    //"mysql"指定数据库类型，  /test指定打开的数据库  root:123 冒号隔开密码 root账号 123密码
    database, err := sqlx.Open("mysql", "root@tcp(127.0.0.1:3306)/test")
    if err != nil {
        fmt.Println("open mysql failed,", err)
        return
    }
    Db = database
}
func main() {
    //事务操作
    conn, err := Db.Begin()
    if err != nil {
        return
    }

    //插入数据入表
    r, err := Db.Exec("insert into person(username,sex,email)values(?,?,?)", "chaoge", "man", "yc_uuu@163.com")
    if err != nil {
        fmt.Println("exec failed,", err)
        return
    }

    id, err := r.LastInsertId()
    if err != nil {
        fmt.Println("exec failed,", err)
        //回滚
        conn.Rollback()
        return
    }
    fmt.Println("insert succ:", id)
　　　　//提交事务
    conn.Commit()
}

Golang之http编程

Go原生支持http。import("net/http")
Go的http服务性能和nginx比较接近
几行代码就可以实现一个web服务

服务端http

package main

import (
    "fmt"
    "net/http"
)

func Hello(w http.ResponseWriter, r *http.Request) {
    fmt.Println("handle hello")
    fmt.Fprintf(w, "hello")
}
func Login(w http.ResponseWriter, r *http.Request) {
    fmt.Println("handle login")
    fmt.Fprintf(w, "login....")
}


func main() {
    http.HandleFunc("/", Hello)
    http.HandleFunc("/user/login", Login)
    err := http.ListenAndServe("127.0.0.1:8800", nil)
    if err != nil {
        fmt.Println("htpp listen failed")
    }
}

http客户端

package main

import (
    "fmt"
    "io/ioutil"
    "net/http"
)

func main() {
    res, err := http.Get("https://www.baidu.com/")
    if err != nil {
        fmt.Println("get err:", err)
        return
    }
    data, err := ioutil.ReadAll(res.Body)
    if err != nil {
        fmt.Println("get data err:", err)
        return
    }
    fmt.Println(string(data))
}

http_head

package main

import (
    "fmt"
    "net/http"
)

var url = []string{
    "http://www.baidu.com",
    "http://google.com",
    "http://taobao.com",
}

func main() {
    for _, v := range url {
        res, err := http.Head(v)
        if err != nil {
            fmt.Printf("head %s failed,err:%v
", v, err)
            continue
        }
        fmt.Printf("head succ,status:%v
", res.Status)
    }
}

http_head自定义超时写法

package main

import (
    "fmt"
    "net"
    "net/http"

    "time"
)

var url = []string{
    "http://www.baidu.com",
    "http://google.com",
    "http://taobao.com",
}

func main() {
    for _, v := range url {
        //超时写法
        c := http.Client{
            Transport: &http.Transport{
                Dial: func(network, addr string) (net.Conn, error) {
                    timeout := time.Second * 2
                    return net.DialTimeout(network, addr, timeout)
                },
            },
        }
        resp, err := c.Head(v)
        if err != nil {
            fmt.Printf("head %s failed,err:%v
", v, err)
            continue
        }
        fmt.Printf("head succ,status:%v
", resp.Status)
    }
}

http_form写法

package main

import (
   "io"
   "log"
   "net/http"
)

const form = `<html><body><form action="#" method="post" name="bar">
               <input type="text" name="in"/>
               <input type="text" name="in"/>
               <input type="submit" value="Submit"/>
         </form></body></html>`

func SimpleServer(w http.ResponseWriter, request *http.Request) {
   io.WriteString(w, "hello,world")
   panic("test test")
}
func FormServer(w http.ResponseWriter, request *http.Request) {
   w.Header().Set("Content-Type", "text/html")
   switch request.Method {
   case "GET":
      io.WriteString(w, form)
   case "POST":
      request.ParseForm()
      io.WriteString(w, request.Form["in"][1])
      io.WriteString(w, "
")
      io.WriteString(w, request.FormValue("in"))
   }
}

func main() {
   //用函数封装了一下
   http.HandleFunc("/test1", logPanics(SimpleServer))
   http.HandleFunc("/test2", logPanics(FormServer))
   if err := http.ListenAndServe(":8088", nil); err != nil {
   }
}
//捕获，错误处理
func logPanics(handle http.HandlerFunc) http.HandlerFunc {
   return func(write http.ResponseWriter, request *http.Request) {
      defer func() {
         if x := recover(); x != nil {
            log.Printf("[%v]caught panic:%v", request.RemoteAddr, x)
         }
      }()
      handle(write, request) //这里才是
   }
}

http_template，模板写法

package main

import (
    "fmt"
    "os"
    "text/template"
)

type Person struct {
    Name  string
    age   string
    Title string
}

func main() {
    t, err := template.ParseFiles("d:/project/src/go_dev/day10/http_form/index.html")
    if err != nil {
        fmt.Println("parse file err:", err)
        return
    }
    p := Person{Name: "Mary", age: "31", Title: "我的个人网站"}
    if err := t.Execute(os.Stdout, p); err != nil {
        fmt.Println("There was an error:", err.Error())
    }
}

index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>{{.Title}}</title>
</head>
<body>
<p>hello,{{.Name}}</p>
<p>{{.}}</p>   
</body>
</html>

用例2：

package main

import (
    "fmt"
    "html/template"
    "io"
    "net/http"
)

var myTemplate *template.Template

type Result struct {
    output string
}

func (p *Result) Write(b []byte) (n int, err error) {
    fmt.Println("called by template")
    p.output += string(b)
    return len(b), nil
}

type Person struct {
    Name  string
    Title string
    Age   int
}

func userInfo(w http.ResponseWriter, r *http.Request) {
    fmt.Println("handle hello")
    //fmt.Fprintf(w,"hello")
    var arr []Person
    p := Person{Name: "Mary001", Age: 10, Title: "我的网站"}
    p1 := Person{Name: "Mary002", Age: 10, Title: "我的个人网站"}
    p2 := Person{Name: "Mary003", Age: 10, Title: "我的网站2"}
    arr = append(arr, p)
    arr = append(arr, p1)
    arr = append(arr, p2)

    resultWriter := &Result{}
    io.WriteString(resultWriter, "hello world")
    err := myTemplate.Execute(w, arr)
    if err != nil {
        fmt.Println(err)
    }
    fmt.Println("template render data:", resultWriter.output)
    //myTemplate.Execute(w, p)
    //myTemplate.Execute(os.Stdout, p)
    //file, err := os.OpenFile("C:/test.log", os.O_CREATE|os.O_WRONLY, 0755)
    //if err != nil {
    //    fmt.Println("open failed err:", err)
    //    return
    //}
}
func initTemplate(filename string) (err error) {
    myTemplate, err = template.ParseFiles(filename)
    if err != nil {
        fmt.Println("parse file err:", err)
        return
    }
    return
}
func main() {
    initTemplate("d:/project/src/go_dev/day10/template_http/index.html")
    http.HandleFunc("/user/info", userInfo)
    err := http.ListenAndServe("127.0.0.1:8880", nil)
    if err != nil {
        fmt.Println("http listen failed")
    }
}

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
</head>
<body>
<p>hello world</p>
<table border="1">
{{range .}}
    <tr>
        <td>{{.Name}}</td> <td>{{.Age}}</td><td>{{.Title}}</td>
    </tr>
{{end}}
</table>
</body>
</html>