fixed foreign key constraints in database schema
fixed foreign key constraints in database schema

reissmann/ddserver,ddserver/ddserver,ddserver/ddserver,iSC-Labs/ddserver,iSC-Labs/ddserver,reissmann/ddserver,iSC-Labs/ddserver,reissmann/ddserver,ddserver/ddserver,reissmann/ddserver,ddserver/ddserver,iSC-Labs/ddserver