使用Golang操作CnosDB

摘要

• 学习使用CnosDB Golang SDK 操作CnosDB

使用/ping查看cnosdb状态

func ExampleClient_Ping() {

	c, err := client.NewHTTPClient(client.HTTPConfig{
		Addr: "http://localhost:8086",
	})
	if err != nil {
		fmt.Println("Error creating CnosDB Client: ", err.Error())
	}
	defer c.Close()

	_, rs, err := c.Ping(0)
	fmt.Println("version:", rs)
	if err != nil {
		fmt.Println("Error pinging CnosDB: ", err.Error())
	}
}

使用http client写入一个point

func ExampleClient_write() {
	// Make client
	c, err := client.NewHTTPClient(client.HTTPConfig{
		Addr: "http://localhost:8086",
	})
	if err != nil {
		fmt.Println("Error creating CnosDB Client: ", err.Error())
	}
	defer c.Close()

	// Create a new point batch
	bp, _ := client.NewBatchPoints(client.BatchPointsConfig{
		Database:  "oceanic_station",
		Precision: "s",
	})

	// Create a point and add to batch
	tags := map[string]string{"station": "XiaoMaiDao"}
	fields := map[string]interface{}{
		"temperature": 67,
		"visibility":  58,
	}
	pt, err := client.NewPoint("air", tags, fields, time.Now())
	if err != nil {
		fmt.Println("Error: ", err.Error())
	}
	bp.AddPoint(pt)

	// Write the batch
	c.Write(bp)
}

创建一个BatchPoint，并添加一个Point

func ExampleBatchPoints() {
	// Create a new point batch
	bp, _ := client.NewBatchPoints(client.BatchPointsConfig{
		Database:  "oceanic_station",
		Precision: "s",
	})

	// Create a point and add to batch
	tags := map[string]string{"station": "XiaoMaiDao"}
	fields := map[string]interface{}{
		"temperature": 67,
		"visibility":  58,
	}
	pt, err := client.NewPoint("air", tags, fields, time.Now())
	if err != nil {
		fmt.Println("Error: ", err.Error())
	}
	bp.AddPoint(pt)
}

使用BatchPoint的setter方法

func ExampleBatchPoints_setters() {
	// Create a new point batch
	bp, _ := client.NewBatchPoints(client.BatchPointsConfig{})
	bp.SetDatabase("oceanic_station")
	bp.SetPrecision("ms")

	// Create a point and add to batch
	tags := map[string]string{"station": "XiaoMaiDao"}
	fields := map[string]interface{}{
		"temperature": 67,
		"visibility":  58,
	}
	pt, err := client.NewPoint("air", tags, fields, time.Now())
	if err != nil {
		fmt.Println("Error: ", err.Error())
	}
	bp.AddPoint(pt)
}

创建一个point并设置时间戳

func ExamplePoint() {
	tags := map[string]string{"station": "XiaoMaiDao"}
	fields := map[string]interface{}{
		"temperature": 67,
		"visibility":  58,
	}
	pt, err := client.NewPoint("air", tags, fields, time.Now())
	if err == nil {
		fmt.Println("We created a point: ", pt.String())
	}
}

创建一个没有时间戳的point

func ExamplePoint_withoutTime() {
	tags := map[string]string{"station": "XiaoMaiDao"}
	fields := map[string]interface{}{
		"temperature": 67,
		"visibility":  58,
	}
	pt, err := client.NewPoint("air", tags, fields)
	if err == nil {
		fmt.Println("We created a point w/o time: ", pt.String())
	}
}

创建一个查询请求

func ExampleClient_query() {
	// Make client
	c, err := client.NewHTTPClient(client.HTTPConfig{
		Addr: "http://localhost:8086",
	})
	if err != nil {
		fmt.Println("Error creating CnosDB Client: ", err.Error())
	}
	defer c.Close()

	q := client.NewQuery("SELECT temperature FROM air limit 10", "oceanic_station", "ns")
	if response, err := c.Query(q); err == nil && response.Error() == nil {
		fmt.Println(response.Results)
	}
}