A string (e.g. "a string") is a constant. You can't modify it directly in code. You may well have a very good reason for positioning characters within the string. It would inappropriate for perltidy (or other similar software) to modify a constant you've coded. Even without strict and warnings, attempting to modify a constant value is a fatal error:

$ perl -e '"abc" =~ s/c$//'
Can't modify constant item in substitution (s///) at -e line 1, at EOF
Execution of -e aborted due to compilation errors.
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Ditto for numbers:

$ perl -e '2++'
Can't modify constant item in postincrement (++) at -e line 1, near "2
+++"
Execution of -e aborted due to compilation errors.
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Chapter 2 of PBP is devoted to Code Layout. While the focus is obviously on laying out Perl code, many of the suggestions would apply equally to other languages: this might provide a few hints for your SQL.