인프런 커뮤니티 질문&답변

[ARRAY, STRUCT]

 문제 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

쿼리 결과 1)

문제 2) array_exercises 테이블에서 각 영화(title)별로 배우(actor)와 배역(character)을 보여주세요.

SELECT
  title, 
  actor.actor,
  actor.character
FROM advanced.array_exercises
CROSS JOIN UNNEST(actors) AS actor

쿼리 결과 2)

문제 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(genres) AS genre
CROSS JOIN UNNEST(actors) AS actor

쿼리 결과 3)

문제 4) 앱 로그 데이터(app_logs) 배열 풀기

SELECT
  event_date,
  event_timestamp,
  event_name,
  event_param.key AS key,
  event_param.value.string_value AS string_value,
  event_param.value.int_value AS int_value,
  user_id,
  user_pseudo_id,
  platform
FROM `advanced.app_logs`
CROSS JOIN UNNEST(event_params) AS event_param
WHERE event_date = "2022-08-01"
LIMIT 100

쿼리 결과 4)

[PIVOT]

문제 1) orders 테이블에서 유저(user_id)별로 주문 금액(amount)의 합계를 PIVOT해주세요.

날짜(order_date)를 행(Row)으로, user_id를 열(Column)으로 만들어야 합니다.

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

쿼리 결과 1)

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

쿼리 결과 2)

문제 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 ALL
ORDER BY user_id

쿼리 결과 3)

문제 4)user_id = 32888이 카트 추가하기(click_cart)를 누를때 어떤 음식(food_id)을 담았나요?

WITH base AS ( 
  SELECT
  event_date,
  event_timestamp,
  event_name,
  user_id,
  user_pseudo_id,
  MAX(IF(event_param.key = 'firebase_screen',event_param.value.string_value, NULL)) AS firebase_screen,
  MAX(IF(event_param.key = 'food_id',event_param.value.int_value, NULL)) AS food_id,
  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
GROUP BY ALL
) 

SELECT
  user_id,
  event_date,
  COUNT(user_id) AS user_cnt,
  food_id
FROM base
WHERE user_id = 32888 and event_name = 'click_cart'
GROUP BY ALL

쿼리 결과 4)

[퍼널분석]

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

쿼리 결과