부분 집합 요약하기
중급 SQL
Jasmin Ludolf
Data Science Content Developer, DataCamp
집계 함수와 WHERE
SELECT AVG(budget) AS avg_budget
FROM films
WHERE release_year >= 2010;
|avg_budget |
|--------------------|
|41072235.18324607...|
집계 함수와 WHERE
SELECT SUM(budget) AS sum_budget
FROM films
WHERE release_year = 2010;
|sum_budget|
|----------|
|8942365000|
SELECT MIN(budget) AS min_budget
FROM films
WHERE release_year = 2010;
|min_budget|
|----------|
|65000 |
집계 함수와 WHERE
SELECT MAX(budget) AS max_budget
FROM films
WHERE release_year = 2010;
|max_budget|
|----------|
|600000000 |
SELECT COUNT(budget) AS count_budget
FROM films
WHERE release_year = 2010;
|count_budget|
|------------|
|194 |
Round()
- 지정된 소수점 자리로 반올림
SELECT AVG(budget) AS avg_budget
FROM films
WHERE release_year >= 2010;
|avg_budget |
|--------------------|
|41072235.18324607...|
ROUND(number_to_round, decimal_places)
SELECT ROUND(AVG(budget), 2) AS avg_budget
FROM films
WHERE release_year >= 2010;
|avg_budget |
|-----------|
|41072235.18|
정수로 반올림: ROUND()
SELECT ROUND(AVG(budget)) AS avg_budget
FROM films
WHERE release_year >= 2010;
|avg_budget|
|----------|
|41072235 |
SELECT ROUND(AVG(budget), 0) AS avg_budget
FROM films
WHERE release_year >= 2010;
|avg_budget|
|----------|
|41072235 |
음수 매개변수로 반올림: ROUND()
SELECT ROUND(AVG(budget), -5) AS avg_budget
FROM films
WHERE release_year >= 2010;
|avg_budget|
|----------|
|41100000 |
- 숫자형 필드만 해당
연습해봅시다!
중급 SQL
