如何使用Golang InfluxDB Client写入指定_field字段的数据？

希望向InfluxDB写入如下格式的数据点：

{
"_field": "some_uuid",
"_value": float64,
"_time": "2006-01-02T15:04:05.000Z"
}

但实际写入时，UUID被写入到了"field"字段，而非"_field"字段，且"_field"字段默认值为"value"。示例代码如下：

import (
  "fmt"
  influxdb2 "github.com/influxdata/influxdb-client-go/v2"
  "time"
)

type TagData struct {
    TagId     string  `json:"tag_id"`
    Value     float64 `json:"value"`
    Timestamp string  `json:"timestamp"`
}

func main() {
    inflClient := influxdb2.NewClient("my_url", "my_token")
    writeAPI := inflClient.WriteAPI("my_org", "my_bucket")

    data := TagData{
        TagId:     "d8f623a9-c255-4e0d-9c2f-126056875cef",
        Value:     300,
        Timestamp: "2023-12-11T15:35:42.343Z",
    }
    parsedTime, err := time.Parse("2006-01-02T15:04:05.000Z", data.Timestamp)
    if err != nil {
        fmt.Println("Error parsing time:", err)
        return
    }
    point := influxdb2.NewPointWithMeasurement("data").
        AddTag("field", data.TagId).
        AddField("value", data.Value).
        SetTime(parsedTime.UTC())
    writeAPI.WritePoint(point)
    writeAPI.Flush()
    inflClient.Close()
}

解决方法 #

你代码的核心问题是混淆了InfluxDB的Tag和Field概念：你把UUID作为Tag添加，但实际上要让UUID成为_field字段的内容，必须把UUID作为Field的键，数值作为Field的值。

修正后的代码如下：

import (
  "fmt"
  influxdb2 "github.com/influxdata/influxdb-client-go/v2"
  "time"
)

type TagData struct {
    TagId     string  `json:"tag_id"`
    Value     float64 `json:"value"`
    Timestamp string  `json:"timestamp"`
}

func main() {
    inflClient := influxdb2.NewClient("my_url", "my_token")
    writeAPI := inflClient.WriteAPI("my_org", "my_bucket")

    data := TagData{
        TagId:     "d8f623a9-c255-4e0d-9c2f-126056875cef",
        Value:     300,
        Timestamp: "2023-12-11T15:35:42.343Z",
    }
    parsedTime, err := time.Parse("2006-01-02T15:04:05.000Z", data.Timestamp)
    if err != nil {
        fmt.Println("Error parsing time:", err)
        return
    }
    // 修改点：移除AddTag，将UUID作为Field的键传入
    point := influxdb2.NewPointWithMeasurement("data").
        AddField(data.TagId, data.Value).
        SetTime(parsedTime.UTC())
    writeAPI.WritePoint(point)
    writeAPI.Flush()
    inflClient.Close()
}

关键修正说明 #

• 删掉了AddTag("field", data.TagId)：不需要把UUID作为Tag存储
• 将AddField("value", data.Value)改为AddField(data.TagId, data.Value)：这样UUID就会成为_field字段的取值，对应的数值会写入_value字段，完全符合你想要的格式。

内容的提问来源于stack exchange，提问作者Motixa