GoLang 基础知识 mysql相关

将 sql 建表语句转为 struct

https://sql2struct.js.org/

将 rows 转为 Map

// 把rows转换成记录
func makeRowsMap(rows *sql.Rows) []map[string]interface{} {
   colTypes, _ := rows.ColumnTypes()                 // 列信息
   var rowParam = make([]interface{}, len(colTypes)) // 传入到 rows.Scan 的参数 数组
   var rowValue = make([]interface{}, len(colTypes)) // 接收数据一行列的数组

   for i, colType := range colTypes {
      rowValue[i] = reflect.New(colType.ScanType())           // 跟据数据库参数类型，创建默认值 和类型
      rowParam[i] = reflect.ValueOf(&rowValue[i]).Interface() // 跟据接收的数据的类型反射出值的地址
      //logging.Debugf("%s:%s,%s",colType.Name(),colType.ScanType().String(),colType.DatabaseTypeName()) // 字段明称：类型，数据库类型
   }

   var arrays []map[string]interface{} = make([]map[string]interface{},0)
   for rows.Next() {
      rows.Scan(rowParam...)
      record := make(map[string]interface{})
      for i, colType := range colTypes {
         if colType.ScanType().String() == "time.Time" { // 日期要格式化下
            record[colType.Name()] = rowValue[i].(time.Time).Format("2006-01-02 15:04:05")
         }else if colType.DatabaseTypeName() == "NUMERIC" { // number 居然是 interface{} 操蛋[]uint8的数组，后来发现转成string 后在转float
            record[colType.Name()],_ =  strconv.ParseFloat(string(rowValue[i].([]byte)),64)
         }else{
            record[colType.Name()] = rowValue[i]
         }

         //logging.Debugf("%s(%s-%s):%s",colType.Name(),colType.ScanType().String(),colType.DatabaseTypeName(),rowValue[i])

      }
      arrays = append(arrays, record)
   }
   return arrays
}

func byteToFloat64(bytes []byte) float64 {
   bits := binary.LittleEndian.Uint64(bytes)

   return math.Float64frombits(bits)
}