인프런 커뮤니티 질문&답변

ARRAY

-- 1) array_exercises 테이블에서 각 영화(title)별로 장르(genres)를 UNNEST해서 보여주세요.

SELECT
title,
genre
FROM advanced.array_exercises
CROSS JOIN UNNEST(genres) AS genre

--2) array_exercises 테이블에서 각 영화(title)별로 배우(actor)와 배역(character)을 보여주세요. 배우와 배역은 별도의 컬럼으로 나와야 합니다.
SELECT
title,
actor.actor,
actor.character
FROM advanced.array_exercises
CROSS JOIN UNNEST(actors) AS actor

--3) array_exercises 테이블에서 각 영화(title)별로 배우(actor), 배역(character), 장르(genre)를 출력하세요. 한 Row에 배우, 배역, 장르가 모두 표시되어야 합니다.

SELECT
	title,
	actor.actor AS actor,
	actor.character AS character,
	genre
FROM advanced.array_exercises
CROSS JOIN UNNEST(actors) AS actor
CROSS JOIN UNNEST(genres) AS genre
WHERE
 actor.actor = 'Chris Evans'
 AND genre = 'Action'es) AS genre

-- 4) 앱 로그 데이터(app_logs)의 배열을 풀어주세요
WITH base AS (
SELECT
  user_id,
  event_date,
  event_name,
  user_pseudo_id,
  event_param.key AS key,
  event_param.value.string_value AS string_value,
  event_param.value.int_value AS int_value
FROM advanced.app_logs
CROSS JOIN UNNEST(event_params) AS event_param
WHERE
  event_date = '2022-08-01')

PIVOT

--1. orders 테이블에서 유저(user_id)별로 주문 금액(amount)의 합계를 PIVOT 해주세요. 날짜(order_date)를 행(Row)으로, user_id를 열(Column)으로 만들어아 합니다.

SELECT
  order_date,
  MAX(IF(user_id = 1, sum_of_amount, 0)) AS user_1,
  MAX(IF(user_id = 2, sum_of_amount, 0)) AS user_2,
  MAX(IF(user_id = 3, sum_of_amount, 0)) AS user_3  
FROM (
  SELECT
    order_date,
    user_id,
    SUM(amount) AS sum_of_amount
  FROM advanced.orders
  GROUP BY order_date, user_id
)
GROUP BY order_date
ORDER BY order_date

--2.orders 테이블에서 날짜(order_date)별로 유저들의 주문 금액(amount)의 합계를 PIVOT 해주세요. user_id를 행(Row)으로, order_date를 열(Column)으로 만들어야 합니다.

SELECT
  user_id,
  MAX(IF(order_date = "2023-05-01", amount, 0)) AS `2023-05-01`,
  MAX(IF(order_date = "2023-05-02", amount, 0)) AS `2023-05-02`,
  MAX(IF(order_date = "2023-05-03", amount, 0)) AS `2023-05-03`,
  MAX(IF(order_date = "2023-05-04", amount, 0)) AS `2023-05-04`,
  MAX(IF(order_date = "2023-05-05", amount, 0)) AS `2023-05-05`,
FROM advanced.orders
GROUP BY user_id
ORDER BY user_id

--3.orders 테이블에서 사용자(user_id)별, 날짜(order_date)별로 주문이 있다면 1, 없다면 0으로 PIVOT 해주세요. user_id를 행(Row)으로, order_date를 열(Column)로 만들고 주문을 많이 해도 1로 처리합니다.

SELECT
  user_id, 
  MAX(IF(order_date = '2023-05-01', 1, 0)) AS `2023-05-01`,
  MAX(IF(order_date = '2023-05-02', 1, 0)) AS `2023-05-02`,
  MAX(IF(order_date = '2023-05-03', 1, 0)) AS `2023-05-03`,
  MAX(IF(order_date = '2023-05-04', 1, 0)) AS `2023-05-04`,
  MAX(IF(order_date = '2023-05-05', 1, 0)) AS `2023-05-05`,
FROM advanced.orders
GROUP BY user_id

퍼널

WITH base AS (
  SELECT
    event_date,
    event_timestamp,
    event_name,
    user_id,
    user_pseudo_id,
    platform,
    MAX(IF(event_param.key = "firebase_screen", event_param.value.string_value, NULL)) AS firebase_screen,
    MAX(IF(event_param.key = "session_id", event_param.value.string_value, NULL)) AS session_id
  FROM advanced.app_logs
  CROSS JOIN UNNEST(event_params) AS event_param
  WHERE
    event_date BETWEEN "2022-08-01" AND "2022-08-18"
  GROUP BY ALL
), filter_event_and_concat_event_and_screen AS (
  SELECT
    * EXCEPT(event_name, firebase_screen, event_timestamp),
    CONCAT(event_name, "-", firebase_screen) AS event_name_with_screen,
    DATETIME(TIMESTAMP_MICROS(event_timestamp), 'Asia/Seoul') AS event_datetime
  FROM base
  WHERE
    event_name IN ("screen_view", "click_payment")
)
SELECT
  event_date,
  event_name_with_screen,
  CASE 
    WHEN event_name_with_screen = "screen_view-welcome" THEN 1
    WHEN event_name_with_screen = "screen_view-home" THEN 2
    WHEN event_name_with_screen = "screen_view-food_category" THEN 3
    WHEN event_name_with_screen = "screen_view-restaurant" THEN 4
    WHEN event_name_with_screen = "screen_view-cart" THEN 5
    WHEN event_name_with_screen = "click_payment-cart" THEN 6
  ELSE NULL
  END AS step_number,
  COUNT(DISTINCT user_pseudo_id) AS cnt
FROM filter_event_and_concat_event_and_screen
GROUP BY ALL
HAVING step_number IS NOT NULL

아직 SQL 익숙지 않아서, 강의 들으면서 코드를 이해하려고 했습니다.

얼른 빅쿼리 SQL입문 강의도 다 듣고, 2주차에 더 실력이 올라갔으면 좋겠습니다!