[SQL 고득점 Kit] String, Date : 카테고리 별 상품 개수 구하기

https://school.programmers.co.kr/learn/courses/30/lessons/131529

프로그래머스

 

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🚩문자열 자르기

• SUBSTRING()
• SUBSTRING(LOCATE())
• SUBSTRING_INDEX()
• LEFT()
• RIGHT()

 

 

🚩최종 쿼리

SELECT
    SUBSTRING(PRODUCT_CODE, 1, 2) AS CATEGORY,
    COUNT(PRODUCT_ID) AS PRODUCTS
FROM
    PRODUCT
GROUP BY SUBSTRING(PRODUCT_CODE, 1, 2)
ORDER BY CATEGORY