elisp - Emacs region highlighting -

Is there no way to highlight a string in a buffer (but not all these strings) where the font -Lock-mode is ON

Suppose I have a buffer with SQL mode and I want to highlight a string in it.

When I call

  (set-text-property 10 20 '(face hi-yellow))

  (font-lock-mode -1)

This works, but all sql highlighting disappears.

There should be a solution because it is possible to select a region and it will be highlighted but I do not know how to program it

< Div class = "post-text" itemprop = "text">

Both provide a function to highlight markers and highlight areas.

Brennenstuhl