perl -pi.orig -e 's/ where/'' where/g' *.sql
[download]

That's just plain stupid. It's a inconvenient way of writing

perl -pi.orig -e 's/ where/ where/g' *.sql
[download]

and that's clearly not what the poster intended. One could of course in this case switch to double quotes as the shell quotes, but that's not a general solution. The following is:

perl -pi.orig -e 's/ where/'"'"'where/g' *.sql
[download]

and this works too:

perl -pi.orig -e 's/ where/'\''where/g' *.sql
[download]

Abigail