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>`x`</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.