Warn mismatch of bind values

[egawata]

DBIx::Sunny's additional methods accepts bind values, even if the number of them doesn't match with the number of placeholders.

For example, select_row accepts the following usages:

$dbh->select_row("SELECT * FROM student WHERE id = ?");          # too few bind values
$dbh->select_row("SELECT * FROM student WHERE id = ?", 1, 2);   # too many bind values

They will issue the following query. (Output by using DBIx::QueryLog)

[2020-07-27T23:51:24] [DBIx::Sunny::Util] [0.000409] SELECT /* sunny_test.pl line 20 */ * FROM student WHERE id = NULL at lib/DBIx/Sunny/Util.pm line 23
[2020-07-27T23:51:24] [DBIx::Sunny::Util] [0.000364] SELECT /* sunny_test.pl line 21 */ * FROM student WHERE id = '1' at lib/DBIx/Sunny/Util.pm line 23

In the former case, placeholder is replaced with NULL. And in the latter, extra value 2 is ignored.

I think those mismatch would not be what the programmer would intend. It would be safe to warn them.

This PR checks the number of bind values and warn if it doesn't match with the number of placeholders.

[kazeburo]

I think, it's better die or croak when mismatch. @Songmu How do you think?

[Songmu]

I agree with @kazeburo.

Indeed, an exception is raised if there is a mismatch in the argument using the named placeholder currently, so I also think that it is better to match the behavior of the array placeholder as well with throwing an exception when the argument mismatched.

However, we are concerned that throwing an exception may cause an exception in the existing environment.

Nevertheless, as you get it, warnings are often ignored, and it's disastrous when they cause unintended updates to be made. So I also think it is better to throw an exception in such a case.

[egawata]

@kazeburo @Songmu
Thank you for your opinions. As you said, it seems better to throw an exception rather than to warn.
I fixed this at 5f2789a

[kazeburo]

LGTM!

[kazeburo]

I released DBIx-Sunny-0.9992.
Thank you!