openproject/packaging/conf/database.yml

<% url = ENV.fetch('DATABASE_URL') %>
production:
  url: <%= url %>
  <% if url.start_with? 'mysql' %>
  reconnect: true
  variables:
    # These are the default MySql Modes for rails 5.0 only excluding
    # ONLY_FULL_GROUP_BY which would interfere with the current implementation
    # of the query grouping by custom fields.
    sql_mode: "no_auto_value_on_zero,strict_trans_tables,strict_all_tables,no_zero_in_date,no_zero_date,error_for_division_by_zero,no_engine_substitution"
  <% end %>