Database

Database is used in by Open Peer Power as history and tracker only, to store the events and its parameters. The default database used by Open Peer Power is SQLite, and the database file is stored in your configuration directory (e.g., <path to config dir>/.openpeerpower/open-peer-power_v2.db). If you prefer to run a database server (e.g., PostgreSQL), use the recorder component.

To work with the SQLite database manually from the command-line, you will need an installation of sqlite3. Alternatively DB Browser for SQLite provides a viewer for exploring the database data and an editor for executing SQL commands. First load your database with sqlite3:

$ sqlite3 open-peer-power_v2.db
SQLite version 3.13.0 2016-05-18 10:57:30
Enter ".help" for usage hints.
sqlite>

It helps to set some options to make the output more readable:

sqlite> .header on
sqlite> .mode column

You could also start sqlite3 and attach the database later. Not sure what database you are working with? Check it, especially if you are going to delete data.

sqlite> .databases
seq  name             file
---  ---------------  ----------------------------------------------------------
0    main             /home/fab/.openpeerpower/open-peer-power_v2.db

Schema

Get all available tables from your current Open Peer Power database:

sqlite> SELECT sql FROM sqlite_master;

-------------------------------------------------------------------------------------
CREATE TABLE events (
	event_id INTEGER NOT NULL,
	event_type VARCHAR(32),
	event_data TEXT,
	origin VARCHAR(32),
	time_fired DATETIME,
	created DATETIME,
	PRIMARY KEY (event_id)
)
CREATE INDEX ix_events_event_type ON events (event_type)
CREATE TABLE recorder_runs (
	run_id INTEGER NOT NULL,
	start DATETIME,
	"end" DATETIME,
	closed_incorrect BOOLEAN,
	created DATETIME,
	PRIMARY KEY (run_id),
	CHECK (closed_incorrect IN (0, 1))
)
CREATE TABLE states (
	state_id INTEGER NOT NULL,
	domain VARCHAR(64),
	entity_id VARCHAR(64),
	state VARCHAR(255),
	attributes TEXT,
	event_id INTEGER,
	last_changed DATETIME,
	last_updated DATETIME,
	created DATETIME,
	PRIMARY KEY (state_id),
	FOREIGN KEY(event_id) REFERENCES events (event_id)
)
CREATE INDEX states__significant_changes ON states (domain, last_updated, entity_id)
CREATE INDEX states__state_changes ON states (last_changed, last_updated, entity_id)
CREATE TABLE sqlite_stat1(tbl,idx,stat)

To only show the details about the states table (since we are using that one in the next examples):

sqlite> SELECT sql FROM sqlite_master WHERE type = 'table' AND tbl_name = 'states';

Query

The identification of the available columns in the table is done and we are now able to create a query. Let’s list your Top 10 entities:

sqlite> .width 30, 10,
sqlite> SELECT entity_id, COUNT(*) as count FROM states GROUP BY entity_id ORDER BY count DESC LIMIT 10;
entity_id                       count
------------------------------  ----------
sensor.cpu                      28874
sun.sun                         21238
sensor.time                     18415
sensor.new_york                 18393
cover.kitchen_cover             17811
switch.mystrom_switch           14101
sensor.internet_time            12963
sensor.solar_angle1             11397
sensor.solar_angle              10440
group.all_switches              8018

Delete

If you don’t want to keep certain entities, you can delete them permanently:

sqlite> DELETE FROM states WHERE entity_id="sensor.cpu";

The VACUUM command cleans your database.

sqlite> VACUUM;

For a more interactive way of working with the database, check the Data Science Portal.