尝试查找不同的数据时，取回相同的结果

Question

我可以从下面的查询中获取每年的15/02 - 21/06日期范围数据。

SELECT * FROM dim_date
WHERE EXTRACT (MONTH FROM date_cal) BETWEEN 3 AND 5
 OR (EXTRACT (MONTH FROM date_cal) = 2 AND EXTRACT (DAY FROM date_cal) >= 15)
 OR (EXTRACT (MONTH FROM date_cal) = 6 AND EXTRACT (DAY FROM date_cal) <= 21)

但问题是，当我想从年2010 - 2012找到时，我会得到相同的结果。

我想得到的范围：

2010-02-15 - 2010-06-15
2011-02-15 - 2011-06-15
2012-02-15 - 2012-06-15

SELECT * FROM dim_date
WHERE EXTRACT (MONTH FROM date_cal) BETWEEN 3 AND 5
 OR (EXTRACT (MONTH FROM date_cal) = 2 AND EXTRACT (DAY FROM date_cal) >= 15)
 OR (EXTRACT (MONTH FROM date_cal) = 6 AND EXTRACT (DAY FROM date_cal) <= 21)
AND EXTRACT (YEAR FROM date_cal) BETWEEN 2010 AND 2012

谁可以帮我解决这个问题！

Answer 1

你的问题是缺少括号：在SQL中AND优先于OR，所以你需要在前面的整个表达式中加上括号：

SELECT * FROM dim_date
WHERE ( -- added bracket
 EXTRACT (MONTH FROM date_cal) BETWEEN 3 AND 5
 OR (EXTRACT (MONTH FROM date_cal) = 2 AND EXTRACT (DAY FROM date_cal) >= 15)
 OR (EXTRACT (MONTH FROM date_cal) = 6 AND EXTRACT (DAY FROM date_cal) <= 21)
 ) -- added bracket
AND EXTRACT (YEAR FROM date_cal) BETWEEN 2010 AND 2012

如果没有括号，则会获得A or B or (C and D)，但您需要(A or B or C) and D