replies-III

--DROP TABLE Replies; DROP TABLE emails;

CREATE TABLE emails
(
  id serial NOT NULL,
  subject text,
  created_at timestamp without time zone,
  folder text,
  message_id text,
  CONSTRAINT emails_pkey PRIMARY KEY (id)
)
WITH (
  OIDS=FALSE
);

-- Index: emails_message_id_index

-- DROP INDEX emails_message_id_index;

CREATE INDEX emails_message_id_index
  ON emails
  USING btree
  (message_id COLLATE pg_catalog."default");

-- NOT IN THREAD

INSERT INTO emails(
    subject, created_at, folder,  message_id)
    VALUES ('Not part of thread', (NOW() - INTERVAL '100 MINUTE'), 'INBOX', 'CAEBV8YRGwkNSb3cxquS5abSCmnwLn37GxCpg74mQe7=3SC5cdQ@mail.gmail.com');

--THREAD 1 EMAILS

 INSERT INTO emails(
    subject, created_at, folder, message_id)
    VALUES ('howzitgoin', (NOW() - INTERVAL '90 MINUTE'), null, '53856b1448c89_23fa9605badd015951@3a139e8c-0b81-42c2-8e59-133c262e96a9.mail');

INSERT INTO emails(
    subject, created_at, folder, message_id)
    VALUES ('Re: howzitgoin', (NOW() - INTERVAL '80 MINUTE'), 'INBOX', 'CAEBV8YTu_A6LtP_uGuQ-QSVj3zojWUiwcjGZpsPPEz1Pj3_i1A@mail.gmail.com');

 INSERT INTO emails(
    subject, created_at, folder, message_id)
    VALUES ('Re: howzitgoin', (NOW() - INTERVAL '70 MINUTE'), 'INBOX', '53856b88a2a09_23fa9605badd01601b@3a139e8c-0b81-42c2-8e59-133c262e96a9.mail');

INSERT INTO emails(
    subject, created_at, folder, message_id)
    VALUES ('Re: howzitgoin', (NOW() - INTERVAL '60 MINUTE'), 'INBOX', 'CAEBV8YT6vx6buOKUga4f=bcNGq_=WzwiqEzm2FWm3HoLZ8SbJA@mail.gmail.com');

INSERT INTO emails(
    subject, created_at, folder,  message_id)
    VALUES ('Re: howzitgoin', (NOW() - INTERVAL '50 MINUTE'), 'INBOX', 'CAEBV8YRGwkNSb3cxquS5abSCmnwLn37GxCpg74mQe7=3SC5cdQ@mail.gmail.com');

-- THREAD 2 EMAILS

INSERT INTO emails(
    subject, created_at, folder,  message_id)
    VALUES ('thready mercury', (NOW() - INTERVAL '40 MINUTE'), 'INBOX', '[email protected]');

 INSERT INTO emails(
    subject, created_at, folder,  message_id)
    VALUES ('RE: thready mercury', (NOW() - INTERVAL '30 MINUTE'), null, '5386c3c3f364d_23ff44def2de8849cf@55cedd07-f558-4cc4-b5d2-046dc7642b91.mail');

 INSERT INTO emails(
    subject, created_at, folder,  message_id)
    VALUES ('RE: thready mercury', (NOW() - INTERVAL '20 MINUTE'), 'INBOX', '[email protected]');

-- Table: replies

-- DROP TABLE replies;

CREATE TABLE replies
(
  id serial NOT NULL,
  message_id text,
  created_at timestamp without time zone,
  email_id integer NOT NULL,
  CONSTRAINT replies_pkey PRIMARY KEY (id),
  CONSTRAINT replies_email_id_fkey FOREIGN KEY (email_id)
      REFERENCES emails (id) MATCH SIMPLE
      ON UPDATE NO ACTION ON DELETE CASCADE
)
WITH (
  OIDS=FALSE
);


-- Index: replies_email_id_index

-- DROP INDEX replies_email_id_index;

CREATE INDEX replies_email_id_index
  ON replies
  USING btree
  (email_id);

-- Index: replies_message_id_index

-- DROP INDEX replies_message_id_index;

CREATE INDEX replies_message_id_index
  ON replies
  USING btree
  (message_id COLLATE pg_catalog."default");

-- THREAD 1 REPLIES

INSERT INTO replies(message_id, created_at, email_id)
            VALUES ('53856b1448c89_23fa9605badd015951@3a139e8c-0b81-42c2-8e59-133c262e96a9.mail', (NOW() - INTERVAL '85 MINUTE'), 2);

INSERT INTO replies(message_id, created_at, email_id)
            VALUES ('53856b1448c89_23fa9605badd015951@3a139e8c-0b81-42c2-8e59-133c262e96a9.mail', (NOW() - INTERVAL '75 MINUTE'), 3);

INSERT INTO replies(message_id, created_at, email_id)
            VALUES ('CAEBV8YTu_A6LtP_uGuQ-QSVj3zojWUiwcjGZpsPPEz1Pj3_i1A@mail.gmail.com', (NOW() - INTERVAL '75 MINUTE'), 3);

INSERT INTO replies(message_id, created_at, email_id)
            VALUES ('53856b88a2a09_23fa9605badd01601b@3a139e8c-0b81-42c2-8e59-133c262e96a9.mail', (NOW() - INTERVAL '65 MINUTE'), 4);

INSERT INTO replies(message_id, created_at, email_id)
            VALUES ('CAEBV8YTu_A6LtP_uGuQ-QSVj3zojWUiwcjGZpsPPEz1Pj3_i1A@mail.gmail.com', (NOW() - INTERVAL '65 MINUTE'), 4);

INSERT INTO replies(message_id, created_at, email_id)
            VALUES ('53856b1448c89_23fa9605badd015951@3a139e8c-0b81-42c2-8e59-133c262e96a9.mail', (NOW() - INTERVAL '65 MINUTE'), 4);

INSERT INTO replies(message_id, created_at, email_id)
            VALUES ('53856b88a2a09_23fa9605badd01601b@3a139e8c-0b81-42c2-8e59-133c262e96a9.mail', (NOW() - INTERVAL '55 MINUTE'), 5);

INSERT INTO replies(message_id, created_at, email_id)
            VALUES ('CAEBV8YTu_A6LtP_uGuQ-QSVj3zojWUiwcjGZpsPPEz1Pj3_i1A@mail.gmail.com', (NOW() - INTERVAL '55 MINUTE'), 5);

INSERT INTO replies(message_id, created_at, email_id)
            VALUES ('53856b1448c89_23fa9605badd015951@3a139e8c-0b81-42c2-8e59-133c262e96a9.mail', (NOW() - INTERVAL '55 MINUTE'), 5);

-- THREAD 2 REPLIES


INSERT INTO replies(message_id, created_at, email_id)
            VALUES ('[email protected]', (NOW() - INTERVAL '45 MINUTE'), 8);

INSERT INTO replies(message_id, created_at, email_id)
            VALUES ('5386c3c3f364d_23ff44def2de8849cf@55cedd07-f558-4cc4-b5d2-046dc7642b91.mail', (NOW() - INTERVAL '35 MINUTE'), 9);

INSERT INTO replies(message_id, created_at, email_id)
            VALUES ('[email protected]', (NOW() - INTERVAL '35 MINUTE'), 9);

--- my attempt which does not work
SELECT  "emails".id, subject, "count", "emails".created_at
FROM "emails"
LEFT JOIN
(
    SELECT "email_id", count(*) AS "count" FROM "replies" GROUP BY "email_id"
) AS "r"
ON ("emails"."id" = "r"."email_id")
WHERE (("folder" = 'INBOX')
  --AND ("emails"."id" NOT IN (SELECT "email_id" FROM "replies"))
) ORDER BY "created_at" DESC LIMIT 7 OFFSET 0;


--EXPECTED OUTPUT
-----------------------------------------------------------
-- ID | SUBJECT             | COUNT
-- =========================================================
-- 9  | RE: thready mercury | 3
-- 6  | RE: howzitgoin      | 4
-- 1  | Not part of thread  | (null)