MySQL SUM IF字段b =字段a

Question

SELECT 
  incMonth as Month, 
  SUM( IF(item_type IN('typ1', 'typ2') AND incMonth = Month, 1, 0 ) )AS 'Total Sales' 
FROM tester

我只需要当月的总和来循环.

Answer 1

如果我正确阅读,你需要使用group-by或至少where子句将事物限制在你想要的时间范围内:

SELECT incMonth AS Month, SUM(IF(item_type IN('typ1', 'typ2'), 1, 0)) AS 'Total Sales'
FROM tester
GROUP BY incMonth