找出导致 Oracle 错误的数据

Question

我正在尝试在 SQL Developer 中运行 select 语句，该语句将 20160809 之类的字段转换为 date。我的查询看起来像：

select
  to_date(sale_date, 'YYYYMMDD') as sale_date
from properties

这是在抛出ORA-01839: date not valid for month specified。我已经尝试了从子字符串到正则表达式的所有方法，试图推断出哪个值导致了错误，但没有骰子。有什么方法可以执行此查询并获取to_date 的输入导致它失败？

Answer 1

设置：

create table properties(sale_date varchar2(8));
insert into properties values ('20160228');
insert into properties values ('20160230'); 
insert into properties values ('xxxx');

如果你的桌子不是太大，你可以试试这个：

SQL> declare
  2      d date;
  3  begin
  4      for i in (select * from properties) loop
  5          begin
  6              d:= to_date(i.sale_date, 'yyyymmdd');
  7          exception
  8              when others then
  9                  dbms_output.put_line('KO: "' || i.sale_date || '"');
 10          end;
 11      end loop;
 12  end;
 13  /
KO: "20160230"
KO: "xxxx"

PL/SQL procedure successfully completed.

Answer 2

我认为您可能需要一种蛮力方法：

select sale_date
from properties 
where substr(sale_date, 5, 4) not between '0101' and '0131' and
      substr(sale_date, 5, 4) not between '0201' and '0228' and
      substr(sale_date, 5, 4) not between '0301' and '0431' and
      substr(sale_date, 5, 4) not between '0401' and '0430' and
      substr(sale_date, 5, 4) not between '0501' and '0531' and
      substr(sale_date, 5, 4) not between '0601' and '0630' and
      substr(sale_date, 5, 4) not between '0701' and '0731' and
      substr(sale_date, 5, 4) not between '0801' and '0831' and
      substr(sale_date, 5, 4) not between '0901' and '0930' and
      substr(sale_date, 5, 4) not between '1001' and '1031' and
      substr(sale_date, 5, 4) not between '1101' and '1130' and
      substr(sale_date, 5, 4) not between '1201' and '1231';

这不是 100% 完美的。它留下了闰年错误的可能性。您可以使用以下方法手动调查：

select sale_date
from properties 
where sales_date like '%0229';

Answer 3

您使用的是 Oracle 12c 吗？如果是的话，那么

with function safe_to_date(p_string VARCHAR2, p_format VARCHAR2) RETURN DATE IS
BEGIN 
  return to_date(p_string, p_format);
EXCEPTION
  WHEN others THEN
    return NULL;
END;
select sale_date from properties
where sale_date is not null and safe_to_date(sale_date,'YYYYMMDD') IS NULL ;

如果您不在 Oracle 12c 上，您可以将 safe_to_date 放入一个包中，说“my_pkg”，然后：

select sale_date from properties
where sale_date is not null and my_pkg.safe_to_date(sale_date ,'YYYYMMDD') IS NULL ;