这是什么可以被认为是一个错误的组合 - 但实际上可能是至关重要的到Oracle如何使用nlssort
- 以及您的客户端如何处理字符串。在SQL Developer中,例如,当它作为语句或脚本时,这似乎按预期工作,但我无法从工作表或查询结果网格中复制和粘贴结果。
使用dump()
功能,你可以看到,弥补结果的字符:
select dump(utl_raw.cast_to_varchar2((nlssort('"' || CITY_NAME || ', ' || STATE_CODE || '"',
'nls_sort=binary_ai'))) || ' test', 1016) as dumped_result
from (select 'New York' as CITY_NAME, 'NY' as STATE_CODE from dual);
DUMPED_RESULT
----------------------------------------------------------------------------------------------------
Typ=1 Len=20 CharacterSet=AL32UTF8: 22,6e,65,77,20,79,6f,72,6b,2c,20,6e,79,22,0,20,74,65,73,74
^
我标志着^
标记来突出显示在输出0
,投nlssort()
结果与之间您正在添加test
。还是有点更清楚而不串联:
select dump(utl_raw.cast_to_varchar2(nlssort('ABC')), 1016) as dumped_result
from (select 'New York' as CITY_NAME, 'NY' as STATE_CODE from dual);
DUMPED_RESULT
----------------------------------------------------------------------------------------------------
Typ=1 Len=4 CharacterSet=AL32UTF8: 41,42,43,0
甚至更好:
select dump(nlssort('ABC'), 1016) as dumped_result from dual;
DUMPED_RESULT
----------------------------------------------------------------------------------------------------
Typ=23 Len=4: 41,42,43,0
的nlssort()
呼叫添加空字节,显示为转储输出0
,到结果。你的客户端看到,作为字符串的结尾,所以即使Oracle实际上串联字符串,你也看不到结果。
您可以删除null(例如,与rtrim()
,在连接前:
select rtrim(utl_raw.cast_to_varchar2(nlssort('"' || CITY_NAME || ', ' || STATE_CODE || '"',
'nls_sort=binary_ai')), chr(0)) || ' test' as result
from (select 'New York' as CITY_NAME, 'NY' as STATE_CODE from dual);
RESULT
----------------------------------------------------------------------------------------------------
"new york, ny" test
或与较短的原始字符串:
select dump(rtrim(utl_raw.cast_to_varchar2(nlssort('ABC')), chr(0)), 1016) as dumped_result
from (select 'New York' as CITY_NAME, 'NY' as STATE_CODE from dual);
DUMPED_RESULT
----------------------------------------------------------------------------------------------------
Typ=1 Len=3 CharacterSet=AL32UTF8: 41,42,43
,你可以看到现在有没有尾随空字符。
这可能是由于一个“错误”导致'nlssort'添加一个字符串终止符; [here](http://stackoverflow.com/questions/19774073/strange-behavior-of-length-command-oracle)你可以找到更多的东西。例如,如果您尝试从双重'选择转储(utl_raw.cast_to_varchar2((nlssort('something','nls_sort = binary_ai')))),您会看到在字符串末尾添加了“0”字符,所以无论你在这个char之后添加的字符串,都会被忽略,因为它在字符串结尾之后。 – Aleksej
@Aleksej - 我认为这听起来很熟悉,但我找不到之前看到它的地方* 8-)什么是在null之后并不总是完全忽略,整个串联的字符串显示在SQL Developer中,例如,但即使真的(不能复制/粘贴),它也不处于可用状态。 –