MySql query to insert row with multiple conditions

I need to add a new row for all post_ids that equal specific condition. So there is a table with post_id, meta_key and meta_value

I need to add for post_id that has meta_key = "page-type" and meta_value = "city" while meta_key = "banner" does not exist. In this example I should have a new row

Of course the table contains about 200K such rows 🙂
Any suggestions?

>Solution :

INSERT INTO
  post (
    post_id,
    meta_key,
    meta_value
  )
SELECT
  post_id,
  'banner',
  '"my new banner"'
FROM
  your_meta_table
GROUP BY
  post_id
HAVING
  MAX(CASE WHEN meta_key = 'banner' THEN 1 ELSE 0 END) = 0
  AND
  MAX(CASE WHEN meta_key = 'page-type' AND meta_value = 'city' THEN 1 ELSE 0 END) = 1

Or, preferably…

INSERT INTO
  post (
    post_id,
    meta_key,
    meta_value
  )
SELECT
  post_id,
  'banner',
  '"my new banner"'
FROM
  your_posts_table
WHERE
  NOT EXISTS (
    SELECT *
      FROM your_meta_table
     WHERE post_id = your_posts_table.post_id
       AND meta_key = 'banner'
  )
  AND EXISTS (
    SELECT *
      FROM your_meta_table
     WHERE post_id = your_posts_table.post_id
       AND meta_key = 'page-type'
       AND meta_value = 'city'
  )