convert a mysql table to utf8mb4 (useful for migration to mb4 on Nextcloud)

mysql_convert_mb4.sh

#!/bin/bash
#
# CHANGE VALUES OF DATABASE AND MYSQL TO MATCH YOUR SETUP

DATABASE="devncmaster"
MYSQL="mysql -N --database=$DATABASE"

# convert database with all tables to utf8mb4
echo "ALTER DATABASE $DATABASE CHARACTER SET = utf8mb4 COLLATE = utf8mb4_bin;" | $MYSQL

echo 'show tables' | eval $MYSQL | while read table
do
    echo "ALTER TABLE $table ROW_FORMAT=DYNAMIC;" | 
        eval $MYSQL
    echo "ALTER TABLE $table CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_bin;" | 
        eval $MYSQL
done