带字符串的Oracle SQL无效数字错误

Question

我有这样的查询...

SELECT 1,2,3 
FROM (SELECT CASE WHEN something THEN TO_CHAR(1)... END,2,3 
      FROM tables WHERE condtions) 
      WHERE 1 NOT LIKE 'String'

所有列都是varchar2，在此查询中，我指向内部case语句时收到“ Invalid Number”错误。 内部查询单独运行良好..如果删除外部WHERE条件，则整个查询运行良好。

我知道这与SQL Optimizer有所关系，但是我在这里做错了什么，如何解决呢？ 对字符串或外部select语句使用To_CHAR不起作用...

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更新以更好地理解，

SELECT COL1, COL2, COL3 FROM (
SELECT CASE WHEN LOGIC THEN TO_CHAR(1) ELSE TO_CHAR(0) END AS COL1, 
COUNT(SOME_COL) AS  COL2 , COUNT(SOME_COL2) AS COL3 FROM TABLES WHERE CONDTIONS
) WHERE COL1 NOT LIKE ‘0’

有人告诉我Oracle SQL Optimizer正在干扰并导致上述错误，并且查询必须以其他方式编写。

Answer 1

通过用反斜线括起来，表明1是列名。

SELECT 1,2,3 FROM (SELECT CASE WHEN something THEN TO_CHAR(1)... END,2,3 
FROM tables
WHERE condtions) WHERE `1` NOT LIKE 'String'

Answer 2

您需要使用适当的列名（以字母开头）-1,2,3将不起作用（除非加引号）：

create table tab1 as 
select 1 as pk from dual
union all
select 2 as pk from dual
union all
select 3 as pk from dual;

SELECT col1,col2,col3 
FROM (SELECT (CASE WHEN 1=2 THEN TO_CHAR(1) else to_char(2) END) as col1 ,
      2 as col2,
      3 as col3
      FROM tab1 WHERE pk > 1) 
      WHERE col1 NOT LIKE '%1%'