One-liner to convert an existing Home-Assistant SQLite database to MySQL

convert_ha_sqlite2mysql.sh

# prerequisites:
## install software
apt install mariadb-server libmariadbclient-dev sqlite3
## install mysqlclient in virtualenv
su -c 'homeassistant/bin/pip3 install mysqlclient --upgrade' -l homeassistant
## create database
mysql -e 'CREATE SCHEMA IF NOT EXISTS `hass_db` DEFAULT CHARACTER SET utf8'
## create user (use a safe password please)
mysql -e "CREATE USER 'hass_user'@'localhost' IDENTIFIED BY 'hass_pw'"
mysql -e "GRANT ALL PRIVILEGES ON hass_db.* TO 'hass_user'@'localhost'"
mysql -e "GRANT usage ON *.* TO 'hass_user'@'localhost'"
# stop HA now
systemctl stop home-assistant # or whatever it is for you
# now edit the configuration to point hass to mysql
nano ....
# now start HA once and stop it right away, we only want it to create the tables:
systemctl start home-assistant # or whatever it is for you
sleep 20
systemctl stop home-assistant # or whatever it is for you
# now empty the tables
mysql hass_db -e 'delete from events;delete from recorder_runs; delete from schema_changes; delete from states;'

# this is the actual conversion:
sqlite3 home-assistant_v2.db .dump \
| sed -re 's/^PRAGMA .+OFF/SET FOREIGN_KEY_CHECKS=0;SET UNIQUE_CHECKS=0/' \
       -e 's/^CREATE INDEX .+//' \
       -e 's/^BEGIN TRANSACTION;$/SET autocommit=0;BEGIN;/' \
       -e '/^CREATE TABLE .+ \($/,/^\);/ d' \
       -e 's/^INSERT INTO "([^"]+)"/INSERT INTO \1/' \
       -e 's/\\n/\n/g' \
| perl -pe 'binmode STDOUT, ":utf8";s/\\u([0-9A-Fa-f]{4})/pack"U*",hex($1)/ge' \
| mysql hass_db --default-character-set=utf8 -u hass_user -p

Im very novice here...
I'm using HAOS and have MariaDB addon installed.
It looks like the instructions install mariaDB at HAOS root? Im not sure how to SSH into the addon.

Is this the correct way to migrate for HAOS users?
Is it possible for detailed steps for a real novice HAOS users, like myself?

Aside from that, I had problems converting unicode characters - a lot of entries in states had unicode \u00b0C that was copied as ?C for example, but an update/replace query sorted that out..

@kaitlinsm Could you give an example of what this query looked like?

I ended up using the sqlite3-to-mysql python script
So far it seems to work well.
Also utf8mb4 seems to be default on my ubuntu server setup

# prerequisites:
## install software
apt install mariadb-server
## create database
mysql -e 'CREATE SCHEMA IF NOT EXISTS `hass_db` DEFAULT CHARACTER SET utf8mb4'
## create user (use a safe password please)
mysql -e "CREATE USER 'hass_user'@'localhost' IDENTIFIED BY 'hass_pw'"
mysql -e "GRANT ALL PRIVILEGES ON hass_db.* TO 'hass_user'@'localhost'"
mysql -e "GRANT usage ON *.* TO 'hass_user'@'localhost'"
# stop HA now
docker stop homeassistant # or whatever it is for you
# now edit the configuration to point hass to mysql
nano ....
# convert the sqlite db to mysql
sqlite3mysql -f ./home-assistant_v2.db -d hass_db -u hass_user -p
# start HA
docker start homeassistant # or whatever it is for you

I ended up using the sqlite3-to-mysql python script So far it seems to work well. Also utf8mb4 seems to be default on my ubuntu server setup

# prerequisites:
## install software
apt install mariadb-server
## create database
mysql -e 'CREATE SCHEMA IF NOT EXISTS `hass_db` DEFAULT CHARACTER SET utf8mb4'
## create user (use a safe password please)
mysql -e "CREATE USER 'hass_user'@'localhost' IDENTIFIED BY 'hass_pw'"
mysql -e "GRANT ALL PRIVILEGES ON hass_db.* TO 'hass_user'@'localhost'"
mysql -e "GRANT usage ON *.* TO 'hass_user'@'localhost'"
# stop HA now
docker stop homeassistant # or whatever it is for you
# now edit the configuration to point hass to mysql
nano ....
# convert the sqlite db to mysql
sqlite3mysql -f ./home-assistant_v2.db -d hass_db -u hass_user -p
# start HA
docker start homeassistant # or whatever it is for you

This method worked for me. Awesome. You're a star.

If you are getting error:

2022-07-12 09:32:29 ERROR 2003: Can't connect to MySQL server on 'localhost:3306' (111 Connection refused)
2003: Can't connect to MySQL server on 'localhost:3306' (111 Connection refused)

Let´s try this way:

sqlite3mysql -f ./config/home-assistant_v2.db -d hass_db -u hass_user -h core-mariadb -p