if col == None or isinstance(col, Code): return col

    else: return Col(col, table)

    def __init__(self, name, code):

        Col.__init__(self, name)

class ValueCond:

    def __init__(self, value):

        if not isinstance(value, Code): value = Literal(value)

        self.value = value

        tables to join with it using the main input table's pkey

    @param mapping dict(out_table_col=in_table_col, ...)

        * out_table_col: sql_gen.Col|str

    @return sql_gen.Col Where the output pkeys are made available

    '''

    for in_table_col in mapping.itervalues():

            except KeyError: # no mapping for missing col, so every row invalid

                db.log_debug('Missing mapping for '+out_col)

                run_query_into_pkeys(*mk_select(db, insert_joins,

                break

            else:

                log_ignore(in_col, 'NULL')

                value), in_table)

        else: # value is literal value; should only be string or None

            assert util.is_str(value) or value == None

    # Insert node

    pkeys_loc = sql.put_table(db, out_table, in_tables, row, limit, start,