Documentation is a bit vague about sqlite3_normalized_sql fct so I'm not sure if this is a bug.
 
select 1 as x;
select 1 as [x];
select 1 as "x";
select 1 as `x`;

Normalized sql for above 4 is
SELECT?AS x;

but for
select 1 as 'x';
it's
SELECT?AS?;

This is a string literal containing a single character U+0078:

  *  `'x'`

These forms are all different spellings for an identifier that consists
of a single character U+0078:

  *   `x`
  *   `[x]`
  *   `"x"`
  *   <tt>&#96;x&#96;</tt>

The sqlite3_normalize_sql() interface should convert literals into "?" and
convert identifiers into their simplest form.  It appears to be doing
the right thing in your example.

It was the "converting identifiers to their simplest form" that I found useful Richard but this does make it less so. If I wanted to interpret user sql and they input

select "tbl" . [col] from tbl;

it will be normalized to

SELECT tbl.col FROM tbl; -- useful

but

select "tbl" . 'col' from tbl;

will be normalized to

SELECT tbl.?FROM tbl; -- less useful

although both the original sql's will return the exact same result.

I'm guessing that I'm using sqlite3_normalized_sql for something it's not intended for. Wish I knew what it was intended for though.

The statement:

   SELECT "tbl".'col' FROM tbl;

Is *not* standard SQL.  SQLite accepts it in a misguided effort to follow
[Postel's Rule][1].  But that does not make it right.  The conversion
of the string literal `'col'` into an identifier `"col"` occurs during
parsing and requires a level of understanding of the SQL language far in
excess of what is available to sqlite3_normalize_sql().

I'm not sure the automatic conversion of string-literals into identifiers
is even documented.  Is it?

[1]: https://en.wikipedia.org/wiki/Robustness_principle

OK Richard, thanks for the input.

Does SQLITE_ENABLE_NORMALIZE have to be defined for sqlite3_normalized_sql to work? I just undefined it and it works as before yet I see
#ifdef SQLITE_ENABLE_NORMALIZE
throughout the sqlite3.c code.