java - 从数据库查询中过滤值

Question

我使用以下过滤器从数据库中获取值:

提交表单时，我执行以下查询:

  SELECT id, Month, Year, SUM(3R02) AS 3R02, SUM(3R05) AS 3R05 
    FROM varcosts 
   WHERE (    Month = 03 
          AND Month = 02 
          AND Year = 2013) 
      OR (    Month = 03 
          AND Month = 02 
          AND Year = 2014) 
GROUP BY Year, Month

由于我使用servlet 来执行查询，因此实现此查询变得很麻烦。就像一个问题，有没有更简单的方法来编写这个查询？我正在寻找一种方法，可以将用户选择的所有月份都包含在复选框中，而无需为每个月重复 AND Month = ..。有简单的解决方案吗？

Answer 1

您可以使用 IN 语句来完成:

  SELECT id, Month, Year, SUM(3R02) AS 3R02, SUM(3R05) AS 3R05 
    FROM varcosts 
   WHERE (    Month IN(03,02)   
          AND Year = 2013) 
      OR (    Month IN (02,03)
          AND Year = 2014) 
GROUP BY Year, Month