I once debugged a case where the id had left sided zero padding so the whole id length was a fixed number of digits, for example `238974` might be represented as `00238974`.

In a process that joined two tables the match counts were off. Somehow, on one side of the join the id was being converted to an integer and then back to a string, which stripped the zero padding. Meaning that `00238974` was failing to match `238974`.

Sigh.