return list(col_names(select(db, table, limit=0, order_by=None,

        recover=recover)))

    '''Creates a mapping from original column names (which may have collisions)

    to names that will be distinct among the given tables.

    This is meant to be used for several tables that are being joined together.

    @param preserve [sql_gen.Col...] Columns not to rename. The tables of the

        them if you want to keep the original tables.

    @return dict(orig_col=new_col, ...)

        * orig_col: sql_gen.Col(orig_col_name, orig_table)

          changed for all columns at once

    '''

    flatten_mapping = {}

    for table in tables:

        for col in table_cols(db, table):

            col = sql_gen.as_Col(col, table)

    for col in preserve:

        orig_col = copy.copy(col)

        flatten_mapping[orig_col] = col

    return flatten_mapping

    '''For params, see mk_flatten_mapping()

    @return See return value of mk_flatten_mapping()

    '''

    tables = joins[:1]+[v.table for v in joins[1:]]

    cols = [sql_gen.NamedCol(new.name, old) for old, new in mapping.iteritems()]

    run_query_into(db, *mk_select(db, joins, cols, limit=limit, start=start),

    return mapping

def pkey(db, table, recover=None):