def insert_ignore data_hash = {}
    sql, *binds = SQLHelper.insert_ignore :table => name,
                                          :data => @query_default.merge(data_hash),
                                          :prepared => true
    pstmt = prepare :insert, sql
    pstmt.set_fetch_size @fetch_size if @fetch_size
    pstmt.send @update_method, *binds
  end
def insert_ignore data_hash = {}
    sql, *binds = SQLHelper.insert_ignore :table => name,
                                          :data => @query_default.merge(data_hash),
                                          :prepared => true
    pstmt = prepare :insert, sql
    pstmt.set_fetch_size @fetch_size if @fetch_size
    pstmt.send @update_method, *binds
  end
Inserts a record into the table with the given hash.
 Skip insertion when duplicate record is found.
 @note This is not SQL standard. Only works if the database supports insert ignore syntax.
 @param [Hash] data_hash Column values in Hash
 @return [Fixnum] Number of affected records