--- sidebar_label: OpentsDB JSON 格式协议 title: OpentsDB JSON 格式协议 --- import Tabs from "@theme/Tabs"; import TabItem from "@theme/TabItem"; import JavaJson from "./_java_opts_json.mdx"; import PyJson from "./_py_opts_json.mdx"; import GoJson from "./_go_opts_json.mdx"; import RustJson from "./_rust_opts_json.mdx"; import NodeJson from "./_js_opts_json.mdx"; import CsJson from "./_cs_opts_json.mdx"; import CJson from "./_c_opts_json.mdx"; ## 协议介绍 OpentsDB JSON 格式协议采用一个 JSON 字符串表示一行或多行数据。例如: ```json [ { "metric": "sys.cpu.nice", "timestamp": 1346846400, "value": 18, "tags": { "host": "web01", "dc": "lga" } }, { "metric": "sys.cpu.nice", "timestamp": 1346846400, "value": 9, "tags": { "host": "web02", "dc": "lga" } } ] ``` 与 OpentsDB 行协议类似, metric 将作为超级表名, timestamp 表示时间戳,value 表示度量值, tags 表示标签集。 参考[OpenTSDB HTTP API文档](http://opentsdb.net/docs/build/html/api_http/put.html)。 :::note - 对于 JSON 格式协议,TDengine 并不会自动把所有标签转成 nchar 类型, 字符串将将转为 nchar 类型, 数值将同样转换为 double 类型。 - TDengine 只接收 JSON **数组格式**的字符串,即使一行数据也需要转换成数组形式。 ::: ## 示例代码 以上示例代码会自动创建 2 个超级表, 每个超级表有 2 条数据。 ```cmd taos> use test; Database changed. taos> show stables; name | created_time | columns | tags | tables | ============================================================================================ meters.current | 2022-03-29 16:05:25.193 | 2 | 2 | 1 | meters.voltage | 2022-03-29 16:05:25.200 | 2 | 2 | 1 | Query OK, 2 row(s) in set (0.001954s) taos> select * from `meters.current`; ts | value | groupid | location | =================================================================================================================== 2022-03-28 09:56:51.249 | 10.300000000 | 2.000000000 | Beijing.Chaoyang | 2022-03-28 09:56:51.250 | 12.600000000 | 2.000000000 | Beijing.Chaoyang | Query OK, 2 row(s) in set (0.004076s) ```