golang學習總結（一）

golang使用mysql

• golang連接mysql

使用orm框架，先下載package，在Terminal下執行go get -u github.com/jinzhu/gorm，創建main.go測試文件，代碼如下。

package main

import (
	"fmt"
	"strings"
	"time"

	"github.com/jinzhu/gorm"
	_ "github.com/jinzhu/gorm/dialects/mysql"
	"github.com/spaolacci/murmur3"
)
//定義表字段
type Test struct {
	Id  int
	Num int
}

type View struct {
	ID        int    `gorm:"primary_key"`
	Ip        string `gorm:"type:varchar(20);not null;index:ip_idx"`
	Ua        string `gorm:"type:varchar(256);not null;"`
	Title     string `gorm:"type:varchar(128);not null;index:title_idx"`
	Hash      uint64
	CreatedAt time.Time
}

type Like struct {
	ID        int    `gorm:"primary_key"`
	Ip        string `gorm:"type:varchar(20);not null;index:ip_idx"`
	Ua        string `gorm:"type:varchar(256);not null;"`
	Title     string `gorm:"type:varchar(128);not null;index:title_idx"`
	Hash      uint64 `gorm:"unique_index:hash_idx;"`
	CreatedAt time.Time
}

type Comment struct {
	ID        int    `gorm:"primary_key"`
	Ip        string `gorm:"type:varchar(20);not null;"`
	Ua        string `gorm:"type:varchar(256);not null;"`
	Title     string `gorm:"type:varchar(128);not null;index:title_idx"`
	Content   string `gorm:"type:varchar(1024);not null;"`
	Nickname  string `gorm:"type:varchar(64);"`
	Mail      string `gorm:"type:varchar(256);"`
	CreatedAt time.Time
}

func createTables(db *gorm.DB) {
	db.CreateTable(&Test{})
}

func main() {
	db, err := gorm.Open("mysql", "test:Pass1234@(localhost:3306)/world?charset=utf8&parseTime=True&loc=Local")
	if err == nil {
		fmt.Println("open db sucess")
	} else {
		fmt.Println("open db error ", err)
		return
	}

	if !db.HasTable("tests") {
		createTables(db)
	}

	if !db.HasTable(&View{}) {
		if err := db.Set("gorm:table_options", "ENGINE=InnoDB DEFAULT CHARSET=utf8").CreateTable(&View{}).Error; err != nil {
			panic(err)
		}
	}
	if !db.HasTable(&Like{}) {
		if err := db.Set("gorm:table_options", "ENGINE=InnoDB DEFAULT CHARSET=utf8").CreateTable(&Like{}).Error; err != nil {
			panic(err)
		}
	}
	if !db.HasTable(&Comment{}) {
		if err := db.Set("gorm:table_options", "ENGINE=InnoDB DEFAULT CHARSET=utf8").CreateTable(&Comment{}).Error; err != nil {
			panic(err)
		}
	}
        //插入數據
	test := Test{Num: 123456}
	db.Create(&test)
        
	like := Like{Ip: "192.168.183.103", Ua: "ua", Title: "title", Hash: murmur3.Sum64([]byte(strings.Join([]string{"192.168.183.103", "ua", "title"}, "-"))) >> 1, CreatedAt: time.Now()}
	db.Create(&like)
        //查詢數據
	result1 := db.First(&like)
	fmt.Println(result1)

	defer db.Close()
}

1.執行時選擇Debug-Start Debugging(F5)，開始執行時選擇Run Without Debugging(Ctrl+F5)總是報錯說

cannot find module providing package github.com/jinzhu/gorm: working directory is not part of a module

到目前也沒找到root cause。

2.我本地安裝了MySQL數據庫，所以可以直接執行。

3.執行查詢語句時，查出來的結果是如下格式，這一點明天再研究下。

&{{{0 0} 0 0 0 0} 0xc0000884e0 <nil> 1 0xc00014a3c0 false 0 {0xc00018dd60} 0xc00009b340 {{0 0} {{map[gorm:order_by_primary_key:0xc0000a0108] false}} map[] 0} 0xc0001f31e0 <nil> 0xc00008e940 false <nil>}