def visit_foreign_key_constraint(self, constraint):
    local_table = constraint.elements[0].parent.table
    remote_table = constraint.elements[0].column.table
    if (local_table.schema != remote_table.schema):
        return None
    else:
        return super(SQLiteDDLCompiler, self).visit_foreign_key_constraint(constraint)
def visit_foreign_key_constraint(self, constraint):
    local_table = constraint.elements[0].parent.table
    remote_table = constraint.elements[0].column.table
    if (local_table.schema != remote_table.schema):
        return None
    else:
        return super(SQLiteDDLCompiler, self).visit_foreign_key_constraint(constraint)