[FEATURE] I want to keep the comments

[RudolphLiu]

SQL Example

    @Test
    public void test4() throws ParseException, JSQLParserException {
        String orginalSql = "SELECT * FROM  PMS_ROLE_SCALE where ROLE_ID= ? /*if*/\n" +
                "                                and  code_id= ? /*if*/ \n" +
                "/*if*/\n" +
                "            and  SCALE_FLAG=?/*if*/\n" +
                "/*if*/\n" +
                "            and  PMS_TYPE=?/*if*/";
        Statement statement = CCJSqlParserUtil.parse(orginalSql);
        String parsedSql = statement.toString();
        log.info("==> JsqlParser SQL: {}", parsedSql);
    }

I want to keep the comments

I use these comments as placeholders. Since I want to replace these comments after Jsqlparser finishes parsing, I hope that they can still be retained after parsing.

Is there any way to use it? Or is there a better solution?

Also,JSqlParser is a near-perfect work. I often use it in my projects and I love it very much.

[RudolphLiu]

I noticed the issue https://github.com/JSQLParser/JSqlParser/issues/1776 , but still can't think of a good solution

[manticore-projects]

Greetings!

There is no direct way to access such SQL comments because they do not have clear position in the AST. Example:

SELECT /*comment 1*/ /*comment 2*/ column1 from dual;

It's impossible to decide if those comments are properties of the Nodes SELECT or column1 and so the parsed AST can't be easily rewritten into a text.

However, there are certain work arounds:

1. your scan your statements first for comments and determine the "non-whitespace position" of each comment.
   Given, that parsing/de-parsing does not change the content of the SQL, you can insert your comment later again at this "non-whitespace" position.
   I have done exactly this for JSQLFormatter, look-up the Comment-Map implementation.

2. you can access the Special AST Nodes and re-insert into the AST
   This has been done here.