public function addForeignKey($table_column, 
                                  $reference_table, 
                                  $reference_column, 
                                  $delete_cascade = false, 
                                  $update_cascade = false)
    {
        $foreignKey = new \stdClass();
        $foreignKey->table_column     = $table_column;
        $foreignKey->reference_table  = $reference_table;
        $foreignKey->reference_column = $reference_column;
        $foreignKey->delete_cascade   = $delete_cascade;
        $foreignKey->update_cascade   = $update_cascade;
        
        $this->m_foreignKeys[] = $foreignKey;
    }