if函數(shù)作用:
mysql中if函數(shù)是一個(gè)控制流函數(shù),可以根據(jù)一個(gè)條件返回一個(gè)值。
if函數(shù)語法:
IF(expr,if_true_expr,if_false_expr)
if函數(shù)使用方法:
mysql中if函數(shù)通常與sun函數(shù)組合使用
SELECT
SUM(IF(status = 'Shipped', 1, 0)) AS Shipped,
SUM(IF(status = 'Cancelled', 1, 0)) AS Cancelled
FROM
orders;