Question

我是oracle新手，下面是我的SQL。

SELECT * FROM TABLE1 WHERE COLUMN1 = 'YES'
AND COLUMN2 IN (


CASE WHEN EXISTS(SELECT * FROM TABLE1 WHERE COLUMN1 = 'YES' AND COLUMN2 NOT LIKE '%NO%') 
 THEN 
   SELECT COLUMN2 FROM TABLE1 WHERE COLUMN1 = 'YES' AND COLUMN2 NOT LIKE '%YES%'
 ELSE 
   SELECT COLUMN2 FROM TABLE1 WHERE COLUMN1 = 'YES' AND COLUMN2 NOT LIKE '%YES%'  END)

它给出ORA-00936：then语句缺少表达。我在做什么错了？

Answer 1

THEN和ELSE之后的子查询必须用括号括起来：

SELECT * FROM TABLE1 WHERE COLUMN1 = 'YES'
AND COLUMN2 IN (
  CASE 
    WHEN EXISTS (SELECT * FROM TABLE1 WHERE COLUMN1 = 'YES' AND COLUMN2 NOT LIKE '%NO%') 
      THEN (SELECT COLUMN2 FROM TABLE1 WHERE COLUMN1 = 'YES' AND COLUMN2 NOT LIKE '%YES%')
    ELSE (SELECT COLUMN2 FROM TABLE1 WHERE COLUMN1 = 'YES' AND COLUMN2 NOT LIKE '%YES%')
  END
)

仅当这些子查询返回的行数不超过1行时，此方法才有效。
此外，两个子查询都相同。这是错字吗？
由于IN仅返回1个值，因此=可以更改为CASE。

Oracle CASE时-ORA-00936：缺少表达式

1 个答案: