---
layout: page
title: "Database"
description: "Details about the database which Home Assistant is using."
date: 2016-10-10 10:00
sidebar: false
comments: false
sharing: true
footer: true
---

The default database that is used for Home Assistant is [SQLite](https://www.sqlite.org/) and is stored in your [configuration directory](/getting-started/configuration/), eg. `<path to config dir>/.homeassistant/home-assistant_v2.db`. You will need an installation of `sqlite3`, the command-line for SQLite database, or [DB Browser for SQLite](http://sqlitebrowser.org/) which provide an editor for executing SQL commands.
First load your database with `sqlite3`.

```bash
$ sqlite3 home-assistant_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 better readable.

```bash
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.

```bash
sqlite> .databases
seq  name             file
---  ---------------  ----------------------------------------------------------
0    main             /home/fab/.homeassistant/home-assistant_v2.db 
```

### {% linkable_title Schema %}

Get all available tables from your current Home Assistant database.

```bash
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 as we are using that one in the next examples.

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

### {% linkable_title Query %}

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

```bash
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 
```

### {% linkable_title Delete %}

If you don't want to keep certain entities, you can delete them permanently.

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

The `VACUUM` command cleans the your database.

```bash
sqlite> VACUUM;
```

For a more interactive way to work with the database or the create statistics, checkout our [Jupyther notebooks](http://nbviewer.jupyter.org/github/home-assistant/home-assistant-notebooks/blob/master/).

