How to increment a counter in MySQL select but not display (hide) it in the results

Question

Is there a way to increment this counter but not display it in the results? I need to add more text before I can submit this question.

   SET @counter = 0;

   SELECT 
      @counter:=@counter + 1 AS newindex, -- increment the counter that is in the header
      survey_report.id,
      survey_report.survey_row_id as respondent_id, -- the id that copied from the survey table
      survey_report.qid,
      question,
      IF(type IN ('S' , 'K'),
         (SELECT answer
            FROM survey_report
            WHERE qid NOT IN (SELECT qid FROM survey_answers)
            AND survey_questions.language = lang
                  AND survey_report.id = @counter),
         (SELECT answer
            FROM survey_answers
            WHERE survey_questions.qid = survey_answers.qid
                  AND survey_report.qid = survey_questions.qid
                  AND survey_report.answer = survey_answers.code
                  AND survey_answers.language = lang
             )
          ) AS answer
       FROM survey_questions
          JOIN survey_report ON survey_report.qid = survey_questions.qid
          WHERE survey_questions.sid = survey_id
          ORDER BY survey_report.survey_row_id, survey_report.id;

Answer 1

You could always wrap your current query as a subquery and just select the columns you want:

SET @counter = 0;

SELECT
    t.id,
    t.respondent_id,
    t.qid,
    t.question,
    t.answer
FROM
(
    SELECT 
        @counter:=@counter + 1,
        survey_report.id,
        survey_report.survey_row_id as respondent_id,
        survey_report.qid,
        question,
        ...
    FROM survey_questions
    INNER JOIN survey_report
        ON survey_report.qid = survey_questions.qid
    WHERE survey_questions.sid = survey_id
) t
ORDER BY t.respondent_id,
         t.id;

Answer 2

First you can put the init in the same query. to hide the counter you can use this trick.

   SELECT 
      IF(survey_report.id = (@counter := (@counter:=@counter+1)),survey_report.id,survey_report.id) as id
      survey_report.survey_row_id as respondent_id, -- the id that copied from the survey table
      survey_report.qid,
      question,
      IF(type IN ('S' , 'K'),
         (SELECT answer
            FROM survey_report
            WHERE qid NOT IN (SELECT qid FROM survey_answers)
            AND survey_questions.language = lang
                  AND survey_report.id = @counter),
         (SELECT answer
            FROM survey_answers
            WHERE survey_questions.qid = survey_answers.qid
                  AND survey_report.qid = survey_questions.qid
                  AND survey_report.answer = survey_answers.code
                  AND survey_answers.language = lang
             )
          ) AS answer
     FROM survey_questions
     JOIN survey_report ON survey_report.qid = survey_questions.qid
     CROSS JOIN ( SELECT @counter := 0 ) AS init
     WHERE survey_questions.sid = survey_id
     ORDER BY survey_report.survey_row_id, survey_report.id;