Question

我可以将变量输入作为别名是数字吗？

即使我指出NUMBER

，Oracle也会将其转换为CHAR

底部三个很好，因为他们在＆＃39; ＆＃39;

with main_query as (
  select *
  from table
  where criteria = 1
  order by group, value
),
with min_group as (
  select min(group) from main_query
)
select *
from main_query
where group in (select group from min_group);
  -- this where clause should be fast since there will only be 1 record in min_group

Answer 1

Oracle文档说：

DEFINE

DEF [INE] [variable] | [variable = text]

指定用户变量并为其指定CHAR值，或列出单个变量或所有变量的值和变量类型。

所以“define”命令将值保存为chars。

然而，您可以使用to_number将代码中的代码转换为数字，这里是数字变量中成功保存字符（定义值）的示例：

set serveroutput on

DEFINE RecordMonth  = 201401


declare
 Record_Month number;
begin
  select to_number(&RecordMonth) as RecordMonth
  into Record_Month -- number variable
  from dual;
  dbms_output.put_line(Record_Month);
end;

结果是：

201401
PL/SQL procedure successfully completed

定义变量

1 个答案: