Ken Davidson 0f280c1b3c Update database.markdown (#3703)
Minor language edits.
2017-10-22 00:59:44 +02:00

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---
layout: page
title: "Database"
description: "Details about the database which Home Assistant is using."
date: 2016-10-10 10:00
sidebar: true
comments: false
sharing: true
footer: true
redirect_from: /details/database/
---
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/) (e.g., `<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 provides 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 more 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 (since 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 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 [Jupyter notebooks](http://nbviewer.jupyter.org/github/home-assistant/home-assistant-notebooks/tree/master/).