replace characters in notepad++ BUT exclude characters inside single quotation marks

Question

I have a string in this kind:

SELECT column_name FROM table_name WHERE column_name IN ('A' , 'stu' ,'Meyer', ....);

I want replace all characters in notepad++ from upper to lower (or vice versa) BUT, exclude from replacement, characters inside single quotation marks.

condition: It exists no solid structure before/behind the single quotation marks part!

(That means - I can not use the keyword "IN" or signs like "," or "(" or ")" or ";" for this regex ...!)

target string (the characters inside single quotation marks have to stay unchangend):

select column_name from table_name where column_name in ('A' , 'stu' ,'Meyer', ....);

OR (vice versa)

SELECT COLUMN_NAME FROM TABLE_NAME WHERE COLUMN_NAME IN ('A' , 'stu' ,'Meyer', ....);

How can I exclude in notepad++ the single quotation marks part (from replacement)?

(I find the single quotation marks part with e.g. '(.*?)' or '(\w+)' or '[[:alpha:]]{1,}',..)

I'm happy for every answer, also if you don't use notepad++!

Answer 1

Below regex would match all the uppercase letters which are not present inside single quotes.

[A-Z](?=(?:'[^']*'|[^'\n])*$)

Now, right-click on the matched characters and change it to lowercase.

DEMO