Question

我正在尝试运行此SQL查询：

SELECT 
    r.sequence, r.status, r.title, r.duedate, 
    r.related_customer, r.added_by 
FROM
    reminders r, reminders_users ru 
WHERE 
    r.sequence = ru.reminder_seq 
    AND (ru.type = 'user' AND ru.value = '2') 
     OR (ru.value = 'admin' OR ru.value = 'technical_support' 
         OR ru.value = 'sales' OR ru.value = 'accounts') 
    AND r.sequence > '0' 
ORDER BY 
    field(status, '', 'Completed'), duedate ASC

然而，其返回结果为ru.value = '3'

要返回的行是：

reminders.sequence = '883'

reminders_users.reminder_seq = '883'
reminders_users.type = 'user'
reminders_users.value = '3'

我无法看到它如何显示为reminders_users.value = '3'而非'2'

Answer 1

查看值＆＃39; 2＆＃39;，＆＃39; user＆＃39;，＆＃39; admin＆＃39;等，您可能会混淆列值和类型。此外，当混合AND和OR时，请确保直接使用括号。

除了使用显式连接而不是长时间过时的逗号分隔连接语法之外，不要在数字上使用引号，而是在同一个字段上使用IN而不是几个OR。

SELECT 
  r.sequence, r.status, r.title, r.duedate, 
  r.related_customer, r.added_by 
FROM reminders r
JOIN reminders_users ru ON r.sequence = ru.reminder_seq 
WHERE r.sequence > 0
AND
(
  (ru.value = 'user' AND ru.type = 2) 
  OR 
  ru.value IN ('admin', 'technical_support', 'sales', 'accounts')
)  
ORDER BY field(status, '', 'Completed'), duedate ASC;

SQL查询未返回正确的结果

1 个答案: