Question

以下是忽略日期范围。有人可以解释这里出了什么问题吗？不确定某些声明是否需要围绕它的括号，但无论如何都不会理解为什么。

WHERE
     booking_date BETWEEN '2011-11-01' AND '2011-12-21'
 AND booking_status = 'Confirmed'
  OR booking_status = 'Cancelled'
  OR booking_status = 'Rearranged'
 AND invoice_number=''
ORDER BY booking_date ASC

Answer 1

在您的OR条件中加上括号：

WHERE
     booking_date BETWEEN '2011-11-01' AND '2011-12-21'
 AND (booking_status = 'Confirmed'
      OR booking_status = 'Cancelled'
      OR booking_status = 'Rearranged')
 AND invoice_number=''
ORDER BY booking_date ASC

您还可以使用IN，这可能更容易阅读和理解：

WHERE
     booking_date BETWEEN '2011-11-01' AND '2011-12-21'
 AND booking_status IN ('Confirmed', 'Cancelled', 'Rearranged')
 AND invoice_number=''
ORDER BY booking_date ASC

Answer 2

AND比OR高precedence。您的代码被解释为：

WHERE (booking_date BETWEEN '2011-11-01' AND '2011-12-21'
       AND booking_status = 'Confirmed')
OR (booking_status = 'Cancelled')
OR (booking_status = 'Rearranged' AND invoice_number='')

我建议使用IN：

而不是使用OR

WHERE booking_date BETWEEN '2011-11-01' AND '2011-12-21'
AND booking_status IN ('Confirmed', 'Cancelled', 'Rearranged')
AND invoice_number=''

Answer 3

这可能是你想要的：

WHERE booking_date BETWEEN '2011-11-01' AND '2011-12-21'
AND (booking_status = 'Confirmed' OR booking_status = 'Cancelled' OR booking_status = 'Rearranged')
AND invoice_number=''
ORDER BY booking_date ASC"

添加的换行符只是为了更容易阅读。重要的部分是括号。

请查看此页面以获取有关运算符优先级的说明：http://msdn.microsoft.com/en-us/library/ms190276.aspx

Answer 4

可能是你OR给你的问题：

重新格式化：

WHERE booking_date BETWEEN '2011-11-01' AND '2011-12-21' 
AND (booking_status = 'Confirmed' 
    OR booking_status = 'Cancelled' 
    OR booking_status = 'Rearranged') 
AND invoice_number=''
ORDER BY booking_date ASC

您可以添加括号以使其执行您想要的操作（如上所述），或者您甚至可以使用IN子句：

WHERE booking_date BETWEEN '2011-11-01' AND '2011-12-21' 
AND booking_status IN ( 'Confirmed', 'Cancelled', 'Rearranged') 
AND invoice_number=''
ORDER BY booking_date ASC

sql：如何使用如此多的ands正确形成where子句

4 个答案: