本节为您介绍如何使用Connection对象的方法下载算法结果文件，从图集导出点和边。

每个示例主要展示如何使用所列方法。点击完整示例查看完整代码示例。

DownloadAlgoResultFile()

下载当前图集一个算法任务中的一个结果文件。

参数：

• string：文件名称。
• string：生成结果文件的算法任务ID。
• RequestConfig（可选）：请求的配置。如果填入nil，则使用默认的配置。
• func：接收请求结果的函数

返回值：

• error：一个包含发生问题详细信息的错误对象。如果操作成功，则返回nil。

requestConfig := &configuration.RequestConfig{
  UseMaster: true,
  GraphName: "miniCircle",
}

// 在图集miniCircle上运行鲁汶算法并打印任务ID

_, err1 := conn.Uql("algo(louvain).params({phase1_loop_num: 20, min_modularity_increase: 0.001}).write({file:{filename_community_id: 'communityID', filename_ids: 'ids', filename_num: 'num'}})",
  requestConfig)
if err1 != nil {
  println(err1)
}

time.Sleep(5 * time.Second)

myTask, _ := conn.ShowTask("louvain", structs.TaskStatusDone, requestConfig)
myTaskID := myTask[0].TaskInfo.TaskID
println("TaskID is:", myTaskID)

receive := func(data []byte) error {
  var fileName = "communityID"
  filePath := fileName
  file, err := os.Create(filePath)
  if err != nil {
    return err
  }
  defer file.Close()
  _, err = file.Write(data)
  if err != nil {
    return err
  }
  return nil
}

myDownload := conn.DownloadAlgoResultFile("communityID", utils.JSONString(myTaskID), requestConfig, receive)
if myDownload != nil {
  println(myDownload)
} else {
  println("File is downloaded")
}

TaskID is: 65483
File is downloaded

DownloadAllAlgoResultFile()

下载当前图集一个算法任务中的全部结果文件。

参数：

• string：生成结果文件的算法任务ID。
• RequestConfig（可选）：请求的配置。如果填入nil，则使用默认的配置。
• func：接收请求结果的函数

返回值：

• error：一个包含发生问题详细信息的错误对象。如果操作成功，则返回nil。

requestConfig := &configuration.RequestConfig{
  UseMaster: true,
  GraphName: "miniCircle",
}

// 在图集miniCircle上运行鲁汶算法并打印任务ID

_, err1 := conn.Uql("algo(louvain).params({phase1_loop_num: 20, min_modularity_increase: 0.001}).write({file:{filename_community_id: 'communityID', filename_ids: 'ids', filename_num: 'num'}})",
  requestConfig)
if err1 != nil {
  println(err1)
}

time.Sleep(5 * time.Second)

myTask, _ := conn.ShowTask("louvain", structs.TaskStatusDone, requestConfig)
myTaskID := myTask[0].TaskInfo.TaskID
println("TaskID is:", myTaskID)

receive := func(data []byte, filename string) error {
  file, err := os.OpenFile(filename, os.O_CREATE|os.O_WRONLY|os.O_APPEND, os.ModePerm)
  if err != nil {
    panic(err)
  }
  defer file.Close()
  _, err = file.Write(data)
  return nil
}

myDownload := conn.DownloadAllAlgoResultFile(utils.JSONString(myTaskID), requestConfig, receive)
if myDownload != nil {
  println(myDownload)
} else {
  println("Files are downloaded")
}

TaskID is: 65838
Files are downloaded

Export()

从当前图集导出点和边。

参数：

• ExportRequest：导出请求的配置信息，包括dbType:ULTIPA.DBType, schemaName:string, limit:number 和 selectPropertiesName:string[].
• Listener：导出过程的监听器。
• RequestConfig（可选）：请求的配置。如果填入nil，则使用默认的配置。

返回值：

• error：一个包含发生问题详细信息的错误对象。如果操作成功，则返回nil。

// 从图集miniCircle名为account的schema中导出10个点，并打印结果
type MyListener struct {
  Properties []string
}

func (l *MyListener) ProcessNodes(nodes []*structs.Node) error {
  file, err := os.Create("node.csv")
  if err != nil {
    panic(err)
  }
  defer file.Close()
  writer := csv.NewWriter(file)
  defer writer.Flush()
  if nodes != nil {
    for _, node := range nodes {
      var sliceString []string
      for _, key := range l.Properties {
        vv := ConvertDataToString(node.Values.Data[key])
        sliceString = append(sliceString, vv)
      }
      err := writer.Write(sliceString)
      if err != nil {
        panic(err)
      }
    }
  }
  return nil
}

func (l *MyListener) ProcessEdges(edges []*structs.Edge) error {
  file, err := os.Create("edge.csv")
  if err != nil {
    panic(err)
  }
  defer file.Close()
  writer := csv.NewWriter(file)
  defer writer.Flush()
  if edges != nil {
    for _, node := range edges {
      var sliceString []string
      for _, key := range l.Properties {
        vv := ConvertDataToString(node.Values.Data[key])
        sliceString = append(sliceString, vv)
      }
      err := writer.Write(sliceString)
      if err != nil {
        panic(err)
      }
    }
  }
  return nil
}

func ConvertDataToString(value interface{}) string {
  switch value.(type) {
  case int32:
    v := value.(int32)
    str := strconv.FormatInt(int64(v), 10)
    return str
  case string:
    v := value.(string)
    return v
  case int64:
    v := value.(string)
    return v
  case []interface{}:
    var slic []string
    for _, val := range value.([]interface{}) {
      if vv, ok := val.(string); ok {
        slic = append(slic, vv)
      }
      if vv, ok := val.(int32); ok {
        vvv := strconv.FormatInt(int64(vv), 10)
        slic = append(slic, vvv)
      }
    }
    result := strings.Join(slic, ",")
    return result
  }
  return ""
}

func main() {

  config, _ := configuration.NewUltipaConfig(&configuration.UltipaConfig{
    Hosts:    []string{"192.168.1.85:60611", "192.168.1.87:60611", "192.168.1.88:60611"},
    Username: "root",
    Password: "root",
  })

  conn, _ := sdk.NewUltipa(config)

  requestConfig := &configuration.RequestConfig{
    UseMaster: true,
    GraphName: "miniCircle",
  }

  var request = ultipa.ExportRequest{
    Schema:           "account",
    SelectProperties: []string{"_id", "_uuid", "year", "name"},
    DbType:           ultipa.DBType_DBNODE,
    Limit:            10,
  }

  myExport := conn.Export(&request, &MyListener{request.SelectProperties}, requestConfig)
  if myExport != nil {
    println(myExport)
  } else {
    println("File is exported")
  }

File is exported

完整示例

package main

import (
  "os"
  "time"

  "github.com/ultipa/ultipa-go-sdk/sdk"
  "github.com/ultipa/ultipa-go-sdk/sdk/configuration"
  "github.com/ultipa/ultipa-go-sdk/sdk/structs"
  "github.com/ultipa/ultipa-go-sdk/utils"
)

func main() {

  // 设置连接
  // URI 示例：Hosts:=[]string{"mqj4zouys.us-east-1.cloud.ultipa.com:60010"}
  config, _ := configuration.NewUltipaConfig(&configuration.UltipaConfig{
    Hosts:    []string{"192.168.1.85:60061", "192.168.1.86:60061", "192.168.1.87:60061"},
    Username: "***",
    Password: "***",
  })

  // 建立与数据库的连接
  conn, _ := sdk.NewUltipa(config)

  // 配置请求
  requestConfig := &configuration.RequestConfig{
    UseMaster: true,
    GraphName: "miniCircle",
  }

  // 运行鲁汶算法并打印任务ID
  _, err1 := conn.Uql("algo(louvain).params({phase1_loop_num: 20, min_modularity_increase: 0.001}).write({file:{filename_community_id: 'communityID', filename_ids: 'ids', filename_num: 'num'}})",
    requestConfig)
  if err1 != nil {
    println(err1)
  }

  time.Sleep(5 * time.Second)

  myTask, _ := conn.ShowTask("louvain", structs.TaskStatusDone, requestConfig)
  myTaskID := myTask[0].TaskInfo.TaskID
  println("TaskID is:", myTaskID) 

  // 下载以上算法任务生成的全部文件，打印每个文件的内容和下载响应信息
  receive := func(data []byte, filename string) error {
    file, err := os.OpenFile(filename, os.O_CREATE|os.O_WRONLY|os.O_APPEND, os.ModePerm)
    if err != nil {
      panic(err)
    }
    defer file.Close()
    _, err = file.Write(data)
    return nil
  }

  myDownload := conn.DownloadAllAlgoResultFile(utils.JSONString(myTaskID), requestConfig, receive)
  if myDownload != nil {
    println(myDownload)
  } else {
    println("Files are downloaded")
  }

}