在PLSQL中将数字转换为varchar2，而PLSQL中没有千位分隔符

Question

有没有一种安全快速的方法将数字转换为 varchar2 而无需千位分隔符（无论排序规则或其他设置如何）。

例子：

/* Normal Collation */
1234.5 => '1234.5' (and not '1,234.5')
1.5 => '1.5'
/* Reverse Collation */
1234.5 => '1234,5' (and not '1.234,5')
1.5 => '1,5'

到目前为止我所拥有的是：

declare
  thousand_separator# varchar2(1);
begin
  thousand_separator# := nullif(substr(to_char(1000), 2, 1), 0);

  dbms_output.put_line(case when thousand_separator# is null then to_char(123456.123) else replace(to_char(123456.123), thousand_separator#) end);
end;

我正在寻找 to_char(<number>, 'CORRECT_FORMAT') 或类似类型的东西（不会添加任何前导零或尾随零）

Answer 1

可以使用the TM 'text minimum'格式模型：

文本最小数字格式模型返回（以十进制输出）可能的最小字符数。

虽然这是你默认得到的，但你使用to_char()，但无论如何都没有模型。

带小数点分隔符的演示：

alter session set nls_numeric_characters = '.,';

with t (num) as (
  select 1234.5 from dual
  union all
  select 1.5 from dual
  union all
  select 0.5 from dual
  union all
  select 0 from dual
  union all
  select 5 from dual
)
select to_char(num, 'TM') as str
from t;

STR                                                             
----------------------------------------------------------------
1234.5
1.5
.5
0
5

begin
  dbms_output.put_line(to_char(123456.123));
end;
/

123456.123

alter session set nls_numeric_characters = ',.';

with t (num) as (
  select 1234.5 from dual
  union all
  select 1.5 from dual
  union all
  select 0.5 from dual
  union all
  select 0 from dual
  union all
  select 5 from dual
)
select to_char(num, 'TM') as str
from t;

STR                                                             
----------------------------------------------------------------
1234,5
1,5
,5
0
5

begin
  dbms_output.put_line(to_char(123456.123));
end;
/

123456,123