Update decimal fields in the PMPro database tables to support more decimals, e.g. Bitcoin

update_pmpro_db_decimals.sql

# Avoid errors in MySQL 5.7
UPDATE wp_pmpro_memberships_users SET enddate = NULL WHERE CAST(enddate AS CHAR(20)) = '0000-00-00 00:00:00';

# Fix membership_levels table
ALTER TABLE `wp_pmpro_membership_levels` MODIFY `initial_payment` decimal(18,8);
ALTER TABLE `wp_pmpro_membership_levels` MODIFY `billing_amount` decimal(18,8);
ALTER TABLE `wp_pmpro_membership_levels` MODIFY `trial_amount` decimal(18,8);

# Fix memberships_users table
ALTER TABLE `wp_pmpro_memberships_users` MODIFY `initial_payment` decimal(18,8);
ALTER TABLE `wp_pmpro_memberships_users` MODIFY `billing_amount` decimal(18,8);
ALTER TABLE `wp_pmpro_memberships_users` MODIFY `trial_amount` decimal(18,8);

# Fix discount_codes_levels table
ALTER TABLE `wp_pmpro_discount_codes_levels` MODIFY `initial_payment` decimal(18,8);
ALTER TABLE `wp_pmpro_discount_codes_levels` MODIFY `billing_amount` decimal(18,8);
ALTER TABLE `wp_pmpro_discount_codes_levels` MODIFY `trial_amount` decimal(18,8);

# Orders table uses varchar