Question

不能完全理解这一个，我有一套条件，只有当一个值在一个字段中时我才能满足。

因此，如果状态完成，我希望有三个where子句，如果状态不等于完成，那么我不想要任何where子句。

代码

SELECT *
FROM mytable
WHERE CASE WHEN Status = 'Complete'
           THEN (included = 0 OR excluded = 0 OR number IS NOT NULL)
           ELSE *Do nothing*

Answer 1

在WHERE中仅使用布尔表达式通常很简单。所以：

WHERE (Status <> 'Complete') OR 
      (included = 0 OR excluded = 0 OR number IS NOT NULL)

如果Status可能是NULL：

WHERE (Status <> 'Complete' OR Status IS NULL) OR 
      (included = 0 OR excluded = 0 OR number IS NOT NULL)

Answer 2

您可以在SQL中翻译自然语言，然后，如果可能，重新制定。

SELECT *
FROM mytable
WHERE (Status = 'Complete' and (included = 0 OR excluded = 0 OR number IS NOT NULL)) 
     or status <> 'Complete'
     or status IS NULL;

Answer 3

看起来你真的不需要CASE语句，只需像这样使用它：

SELECT *
FROM mytable
WHERE where (Status = 'Complete' and (included = 0 OR excluded = 0 OR number IS NOT NULL)) or (*Your do nothing*)

仅当满足条件时，WHERE子句中的Oracle SQL CASE表达式

3 个答案: