sub SET_CLAUSE_LIST
{
    my ( $self, $set_string ) = @_;
    my @sets = split( /,/, $set_string );
    my ( @cols, @vals );
    for my $set (@sets)
    {
        my ( $col, $val ) = split( m/ = /, $set );
        return $self->do_err('Incomplete SET clause!') unless ( defined($col) && defined($val) );
        push( @cols, $col );
        push( @vals, $val );
    }
    return undef
      unless ( $self->{struct}->{column_defs} = $self->ROW_VALUE_LIST( join ',', @cols ) );
    return undef unless ( $self->LITERAL_LIST( join ',', @vals ) );
    return 1;
}