MySQL/ COUNT, AVG, SUM

COUNT

• 데이터의 개수 조회

SELECT COUNT(column_name)
FROM table_name
WHERE condition;

SELECT COUNT(ProductID)
FROM Products;

AVG

• 데이터의 평균 조회

SELECT AVG(column_name)
FROM table_name
WHERE condition;

SELECT AVG(Price)
FROM Products;

SUM

• 데이터의 합계 조회

SELECT SUM(column_name)
FROM table_name
WHERE condition;

SELECT SUM(Quantity)
FROM OrderDetails;