GO将mysql表的数据导出到excel

[weixin_38089851]

```javascript
package main

import (
"log"
"strconv"

_ "github.com/go-sql-driver/mysql"
"github.com/jinzhu/gorm"
"github.com/pikanezi/mapslice"
"github.com/tealeg/xlsx"
)

type Role struct {
Id int `gorm:"primary_key"` //主键id
Name string `gorm:"not null"` //角色名
Remark string
Status int
}

type RoleBack struct {
Id string `json:"id"`
Name string `json:"name"`
Remark string `json:"remark"`
Status string `json:"status"`
}

//规定表名
func (Role) TableName() string {
return "role"
}

var DB *gorm.DB

//初始化并保持连接
func init() {
var err error
DB, err = gorm.Open("mysql", "root:123456@/test?charset=utf8&parseTime=True&loc=Local")
// DB.LogMode(true)//打印sql语句
if err != nil {
log.Fatalf("database connect is err:%s", err.Error())
} else {
log.Print("connect database is success")
}
err = DB.DB().Ping()
if err != nil {
DB.DB().Close()
log.Fatalf("Error on opening database connection: %s", err.Error())
}
}

func main() {
var role RoleBack
var rolelists []RoleBack
rolelist, _ := GetRoleList()
for i := 0; i < len(rolelist); i++ {
role.Id = strconv.Itoa(rolelist[i].Id)
role.Name = rolelist[i].Name
role.Remark = rolelist[i].Remark
role.Status = strconv.Itoa(rolelist[i].Status)
rolelists = append(rolelists, role)
}
id, _ := mapslice.ToStrings(rolelists, "Id")
name, _ := mapslice.ToStrings(rolelists, "Name")
remark, _ := mapslice.ToStrings(rolelists, "Remark")
status, _ := mapslice.ToStrings(rolelists, "Status")

var file *xlsx.File
var sheet *xlsx.Sheet
var row *xlsx.Row
var cell *xlsx.Cell
file = xlsx.NewFile()
sheet, _ = file.AddSheet("Sheet1")
row = sheet.AddRow()
cell = row.AddCell()
cell.Value = "编号"
cell = row.AddCell()
cell.Value = "名称"
cell = row.AddCell()
cell.Value = "状态"
cell = row.AddCell()
cell.Value = "备注"
for i := 0; i < len(id); i++ {
row = sheet.AddRow()
cell = row.AddCell()
cell.Value = id[i]
cell = row.AddCell()
cell.Value = name[i]
cell = row.AddCell()
cell.Value = status[i]
cell = row.AddCell()
cell.Value = remark[i]
file.Save("MyXLSXFile.xlsx")
}
}

func GetRoleList() (rolelist []Role, err error) {
err = DB.Find(&rolelist).Error
return rolelist, err
}

```

[weixin_38113164]

不能用提示 panic: runtime error: invalid memory address or nil pointer dereference