golang 生成对应的数据表struct定义操作

type FieldInfo struct {
 ColName    string `db:"COLUMN_NAME"`
 DataType   string `db:"DATA_TYPE"`
 ColComment string `db:"COLUMN_COMMENT"`
 IsNullable string `db:"IS_NULLABLE"`
}

var dbname= flag.String("db", "", "the database name")
var tblname = flag.String("tbl", "", "the table name to export")
var savepath = flag.String("path", "./", "the path to save file")

func fmtFieldDefine(src string) string {
 temp := strings.Split(src, "_") // 有下划线的，需要拆分
 var str string
 for i := 0; i < len(temp); i++ {
  b := []rune(temp[i])
  for j := 0; j < len(b); j++ {
   if j == 0 {
    // 首字母大写转换
    b[j] -= 32
    str += string(b[j])
   } else {
    str += string(b[j])
   }
  }
 } 
 return str
}

func main() {
 flag.Parse()
 fmt.Println("table name -->", *tblname) 
 dns := fmt.Sprintf("%s:%s@tcp(%s)/%s?charset=utf8", dbuser, dbpwd, dbhost, "information_schema") 
 db := sqlx.MustConnect("mysql", dns)
 
 var fs []FieldInfo
 err := db.Select(&fs, "SELECT COLUMN_NAME, DATA_TYPE, COLUMN_COMMENT, IS_NULLABLE FROM COLUMNS WHERE TABLE_NAME=? and table_schema=?", *tblname, *dbname)
 if err != nil {
  fmt.Println(err)
  panic(err)
 }
 
 if len(fs) > 0 {
  var buffer bytes.Buffer
  buffer.WriteString("package models\n")
  buffer.WriteString("type " + fmtFieldDefine(*tblname) + " struct {\n")
  for _, v := range fs {
   buffer.WriteString("" + fmtFieldDefine(v.ColName) + " ")
   switch v.DataType {
   case "int", "tinyint", "smallint":
    if v.IsNullable == "YES" {
     buffer.WriteString("sql.NullInt64 ")
    } else {
     buffer.WriteString("int ")
    }
   case "bigint":
    if v.IsNullable == "YES" {
     buffer.WriteString("sql.NullInt64 ")
    } else {
     buffer.WriteString("int64 ")
    }
   case "char", "varchar", "longtext", "text", "tinytext":
    if v.IsNullable == "YES" {
     buffer.WriteString("sql.NullString ")
    } else {
     buffer.WriteString("string ")
    }
   case "date", "datetime", "timestamp":
    buffer.WriteString("time.Time ")
   case "double", "float":
    if v.IsNullable == "YES" {
     buffer.WriteString("sql.NullFloat64 ")
    } else {
     buffer.WriteString("float64 ")
    }
   default:
    // 其他类型当成string处理
    if v.IsNullable == "YES" {
     buffer.WriteString("sql.NullString ")
    } else {
     buffer.WriteString("string ")
    }
   }
 
   buffer.WriteString(fmt.Sprintf("`db:\"%s\" JSON:\"%s\"`\n", v.ColName, v.ColName))
 
  }
  buffer.WriteString(`}`) 
  fmt.Println(buffer.String()) 
  filename := *savepath + "\\" + *tblname + ".go"
  f, _ := os.Create(filename)
  f.Write([]byte(buffer.String()))
  f.Close()
 
  cmd := exec.Command("goimports", "-w", filename)
  cmd.Run()
 } else {
  fmt.Println("查询不到数据")
 }
}

package models 
import (
 "database/sql"
 "time"
)
 
type InfoUserShoppingSummary struct {
 Id            int            `db:"id" json:"id"`
 TransactionId sql.NullString `db:"transaction_id" json:"transaction_id"`
 OutTradeNo    sql.NullString `db:"out_trade_no" json:"out_trade_no"`
 WuId          int            `db:"wu_id" json:"wu_id"`
 WdId          int            `db:"wd_id" json:"wd_id"`
 TotalFee      float64        `db:"total_fee" json:"total_fee"`
 PayStaus      sql.NullInt64  `db:"pay_staus" json:"pay_staus"`
 CreateTime    time.Time      `db:"create_time" json:"create_time"`
 UpdateTime    time.Time      `db:"update_time" json:"update_time"`
 Address       sql.NullString `db:"address" json:"address"`
}
 

//Golang的方法定义
//Golang中的方法是作用在特定类型的变量上，因此自定义类型，都可以有方法，不仅仅是struct
//定义：func (recevier type) methodName(参数列表)(返回值列表){}
//方法和函数的区别

package main
//Golang的方法定义
//Golang中的方法是作用在特定类型的变量上，因此自定义类型，都可以有方法，不仅仅是struct
//定义：func (recevier type) methodName(参数列表)(返回值列表){}
import "fmt"
type integer int
func (p integer) print() {
    fmt.Println("p is:", p)
}
//这里传递的是副本，想改变p的值，需要传递指针
func (p *integer) set(b integer) {
    *p = b
}
type Student struct {
    Name  string
    Age   int
    Score int
    sex   int
}
//这里需要接受指针 *Student（接收者），否则修改不了值
func (p *Student) init(name string, age int, score int) {
    p.Name = name
    p.Age = age
    p.Score = score
    fmt.Println(p)
}
func (p Student) get() Student {
    return p
}
func main() {
    var stu Student
    //修改地址的写法(&stu).init
    //但是go可以自动知道，接受者是指针，这里stu就传递地址
    stu.init("stu", 18, 99)
    stu1 := stu.get()
    fmt.Println(stu1)
    //type integer方法
    var a integer
    a = 100
    a.print()
    a.set(1000)
    a.print()
}