Query language and API

In this section, we will discuss InfluxDB query language and how to use InfluxDB API.

Query language

InfluxDB provides an SQL-like query language; it is used for querying time-series data. It also supports HTTP APIs for write and performs admin-related work.

Let's use the InfluxDB CLI tool to connect to an InfluxDB instance and run some queries.

Start and connect to the InfluxDB instance by typing the following commands:

sudo service InfluxDB start
$ influx -precision rfc3339

By default, InfluxDB shows the time as nanosecond UTC value, it is a very long number, like 1511815800000000000. The argument -precision rfc3339 is for the display time field as a human readable format - YYYY-MM-DDTHH:MM:SS.nnnnnnnnnZ:

Connected to http://localhost:8086 version 1.5
InfluxDB shell version: 1.5
>

We can check available databases by using the show databases function:

> show databases;
name: databases
name
----
_internal

To use the command to switch to an existing database, you can type...