Howto connect to Keycloak's default `dev-file` database with the H2 Console:

#!/bin/bash

jar="./lib/lib/main/com.h2database.*.jar"
url="jdbc:h2:file:./data/h2/keycloakdb;NON_KEYWORDS=VALUE;DB_CLOSE_DELAY=0;AUTO_SERVER=TRUE"

java -cp $jar org.h2.tools.Console -url "$url" -user "" -password ""

To be able to connect while running keycloak, use the same connection url, e.g.:

bin/kc.sh start-dev --db-url "jdbc:h2:file:./data/h2/keycloakdb;NON_KEYWORDS=VALUE;DB_CLOSE_DELAY=0;AUTO_SERVER=TRUE"