diff --git a/scripts/psql.sh b/scripts/psql.sh
index 46a3401..9789a29 100644
--- a/scripts/psql.sh
+++ b/scripts/psql.sh
@@ -1,20 +1,62 @@
+#=================================================
+# POSTGRES HELPERS
+#=================================================
+
+# Open a connection as a user
+#
+# example: ynh_psql_connect_as 'user' 'pass' <<< "UPDATE ...;"
+# example: ynh_psql_connect_as 'user' 'pass' < /path/to/file.sql
+#
+# usage: ynh_psql_connect_as user pwd [db]
+# | arg: user - the user name to connect as
+# | arg: pwd - the user password
+# | arg: db - the database to connect to
+ynh_psql_connect_as() {
+	user="$1"
+	pwd="$2"
+	db="$3"
+	su --command="PGUSER=\"${user}\" PGPASSWORD=\"${pwd}\" psql \"${db}\"" postgres
+}
+
 # # Execute a command as root user
 #
 # usage: ynh_psql_execute_as_root sql [db]
 # | arg: sql - the SQL command to execute
 # | arg: db - the database to connect to
 ynh_psql_execute_as_root () {
-	sudo su -c "psql" - postgres <<< ${1}
+	sql="$1"
+	su --command="psql" postgres <<< "$sql"
 }
 
-# Create a user
+# Execute a command from a file as root user
 #
-# usage: ynh_psql_create_user user pwd [host]
-# | arg: user - the user name to create
-# | arg: pwd - the password to identify user by
-ynh_psql_create_user() {
-	ynh_psql_execute_as_root \
-	"CREATE USER ${1} WITH PASSWORD '${2}';"
+# usage: ynh_psql_execute_file_as_root file [db]
+# | arg: file - the file containing SQL commands
+# | arg: db - the database to connect to
+ynh_psql_execute_file_as_root() {
+	file="$1"
+	db="$2"
+	su -c "psql $db" postgres < "$file"
+}
+
+# Create a database, an user and its password. Then store the password in the app's config
+#
+# After executing this helper, the password of the created database will be available in $db_pwd
+# It will also be stored as "psqlpwd" into the app settings.
+#
+# usage: ynh_psql_setup_db user name [pwd]
+# | arg: user - Owner of the database
+# | arg: name - Name of the database
+# | arg: pwd - Password of the database. If not given, a password will be generated
+ynh_psql_setup_db () {
+	db_user="$1"
+	app="$1"
+	db_name="$2"
+	new_db_pwd=$(ynh_string_random)	# Generate a random password
+	# If $3 is not given, use new_db_pwd instead for db_pwd.
+	db_pwd="${3:-$new_db_pwd}"
+	ynh_psql_create_db "$db_name" "$db_user" "$db_pwd"	# Create the database
+	ynh_app_setting_set "$app" psqlpwd "$db_pwd"	# Store the password in the app's config
 }
 
 # Create a database and grant optionnaly privilegies to a user
@@ -22,25 +64,48 @@ ynh_psql_create_user() {
 # usage: ynh_psql_create_db db [user [pwd]]
 # | arg: db - the database name to create
 # | arg: user - the user to grant privilegies
-# | arg: pwd - the password to identify user by
+# | arg: pwd  - the user password
 ynh_psql_create_db() {
-    db=$1
-    # grant all privilegies to user
-    if [[ $# -gt 1 ]]; then
-        ynh_psql_create_user ${2} "${3}"
-        sudo su -c "createdb -O ${2} $db" -  postgres
-    else
-        sudo su -c "createdb $db" -  postgres
-    fi
-
+	db="$1"
+	user="$2"
+	pwd="$3"
+	ynh_psql_create_user "$user" "$pwd"
+	su --command="createdb --owner=\"${user}\" \"${db}\"" postgres
 }
 
 # Drop a database
 #
-# usage: ynh_psql_drop_db db
+# usage: ynh_psql_drop_db db user
 # | arg: db - the database name to drop
-ynh_psql_drop_db() {
-    sudo su -c "dropdb ${1}" -  postgres
+# | arg: user - the user to drop
+ynh_psql_remove_db() {
+	db="$1"
+	user="$2"
+	su --command="dropdb \"${db}\"" postgres
+	ynh_psql_drop_user "${user}"
+}
+
+# Dump a database
+#
+# example: ynh_psql_dump_db 'roundcube' > ./dump.sql
+#
+# usage: ynh_psql_dump_db db
+# | arg: db - the database name to dump
+# | ret: the psqldump output
+ynh_psql_dump_db() {
+	db="$1"
+	su --command="pg_dump \"${db}\"" postgres
+}
+
+
+# Create a user
+#
+# usage: ynh_psql_create_user user pwd [host]
+# | arg: user - the user name to create
+ynh_psql_create_user() {
+	user="$1"
+	pwd="$2"
+        su --command="psql -c\"CREATE USER ${user} WITH PASSWORD '${pwd}'\"" postgres
 }
 
 # Drop a user
@@ -48,21 +113,35 @@ ynh_psql_drop_db() {
 # usage: ynh_psql_drop_user user
 # | arg: user - the user name to drop
 ynh_psql_drop_user() {
-    sudo su -c "dropuser ${1}" - postgres
+	user="$1"
+	su --command="dropuser \"${user}\"" postgres
 }
 
+
 ynh_psql_test_if_first_run() {
 	if [ -f /etc/yunohost/psql ];
 	then
 		echo "PostgreSQL is already installed, no need to create master password"
 	else
-		local pgsql=$(ynh_string_random)
+		pgsql=$(ynh_string_random)
+		pg_hba=""
 		echo "$pgsql" >> /etc/yunohost/psql
+
+		if [ -e /etc/postgresql/9.4/ ]
+		then
+			pg_hba=/etc/postgresql/9.4/main/pg_hba.conf
+		elif [ -e /etc/postgresql/9.6/ ]
+		then
+			pg_hba=/etc/postgresql/9.6/main/pg_hba.conf
+		else
+			ynh_die "postgresql shoud be 9.4 or 9.6"
+		fi
+
 		systemctl start postgresql
-		sudo -u postgres psql -c "ALTER user postgres WITH PASSWORD '${pgsql}'"
-		# we can t use peer since YunoHost create users with nologin
+                su --command="psql -c\"ALTER user postgres WITH PASSWORD '${pgsql}'\"" postgres
+		# we can't use peer since YunoHost create users with nologin
 		sed -i '/local\s*all\s*all\s*peer/i \
-			local all all password' /etc/postgresql/9.4/main/pg_hba.conf
+		local all all password' "$pg_hba"
 		systemctl enable postgresql
 		systemctl reload postgresql
 	fi
diff --git a/scripts/remove b/scripts/remove
index 67cf2b0..108e09f 100755
--- a/scripts/remove
+++ b/scripts/remove
@@ -57,8 +57,7 @@ ynh_secure_remove /etc/systemd/system/matrix-synapse.service
 systemctl daemon-reload
 
 # Remove database and user
-ynh_psql_drop_db $synapse_db_name
-ynh_psql_drop_user $synapse_db_user
+ynh_psql_remove_db $synapse_db_name $synapse_db_user
 
 # Remove user
 ynh_system_user_delete matrix-synapse