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Time Series Database:Overview Of Data Exploration

Last Updated:Aug 03, 2020

InfluxQL is an SQL-like query language that you can use to interact with data in TSDB for InfluxDB®. This topic describes the SELECT statement of InfluxQL and useful query syntax for exploring your data.

Basics Configuration for obtaining query results Suggestion for using query syntax
SELECT statement ORDER BY time DESC Time syntax
WHERE clause LIMIT and SLIMIT clauses Regular expressions
GROUP BY clause OFFSET and SOFFSET clauses Data types and cast operations
INTO clause Time zone clause Merge operations
Multiple statements
Subqueries

Sample data

This topic uses the sample data that is published by the Center for Operational Oceanographic Products and Services (CO-OPS) of National Oceanic and Atmospheric Administration (NOAA). For more information about how to download the data, see the “Sample data” section. The following example shows how to query the data.

Log on to the Influx command-line interface (CLI):

  1. $ influx -ssl -username <Username> -password <Password> -host <Domain name> -port 3242 -precision rfc3339 -database NOAA_water_database
  2. Connected to https://<Domain name>:3242 version 1.7.x
  3. InfluxDB shell 1.7.x
  4. >

Familiarize yourself with the following sample data in the h2o_feet measurement:

name: h2o_feet

time level description location water_level
2015-08-18T00:00:00Z between 6 and 9 feet coyote_creek 8.12
2015-08-18T00:00:00Z below 3 feet santa_monica 2.064
2015-08-18T00:06:00Z between 6 and 9 feet coyote_creek 8.005
2015-08-18T00:06:00Z below 3 feet santa_monica 2.116
2015-08-18T00:12:00Z between 6 and 9 feet coyote_creek 7.887
2015-08-18T00:12:00Z below 3 feet santa_monica 2.028

The data in the h2o_feet measurement occurs at 6-minute intervals. The h2o_feet measurement has one tag key named location. The tag key has two tag values: coyote_creek and santa_monica. The h2o_feet measurement also has two fields: level description that stores the field values of the STRING type and water_level that stores the field values of the FLOAT type. All of the data is stored in the NOAA_water_database database.

Disclaimer: The original NOAA data does not contain the level description field. This field is added to obtain the field values of the STRING type.


InfluxDB® is a trademark registered by InfluxData, which is not affiliated with, and does not endorse, TSDB for InfluxDB®.