Fix find_in_batches against string IDs when start option is not specified

[alexisbernard]

Hi,

Here is a fix for find_in_batches when Model#id is a string. In fact when calling find_in_batches (or find_each) without the start option it generates a wrong SQL statement:

Subscriber.find_each { |subscriber| ...  }
# Generates SQL:
# SELECT  "subscribers".* FROM "subscribers"  WHERE ("subscribers"."nick" >= 0) ...

That statement is invalid with strict databases such as PostgreSQL, because it tries to compare a string against an integer.

With more tolerant databases such as SQLite it's passing, but in fact it skips IDs starting with a lower character than '0'.

Once accepted and merged, I plan to backport that fix in pull request #7987 for rails 3.2.

cc @spastorino

[carlosantoniodasilva]

Wrong indent.

[carlosantoniodasilva]

It needs a changelog entry as well. thanks.

[alexisbernard]

Thanks for pointing those details.

[carlosantoniodasilva]

This line is still bad indented.

[carlosantoniodasilva]

This will need a rebase since github says it cannot be automatically merged anymore, and please squash your commits. Thanks!

[alexisbernard]

Sorry for the poor indentation. I just rebased master into that branch and squashed my commits :)

[carlosantoniodasilva]

@alexisbernard thanks.

[alexisbernard]

Awesome, thanks for the merge.