Oracle9i之前,中文是按照二进制编码进行排序的。在oracle9i中新增了按照拼音、部首、笔画排序功能。
1、设置NLS_SORT参数值
SCHINESE_RADICAL_M 按照部首(第一顺序)、笔划(第二顺序)排序
SCHINESE_STROKE_M 按照笔划(第一顺序)、部首(第二顺序)排序
SCHINESE_PINYIN_M 按照拼音排序
2、Session级别的设置,修改ORACLE字段的默认排序方式:
按拼音:alter session set nls_sort = SCHINESE_PINYIN_M;
按笔画:alter session set nls_sort = SCHINESE_STROKE_M;
按偏旁:alter session set nls_sort = NLS_SORT=SCHINESE_RADICAL_M;
3、语句级别设置排序方式:
按照笔划排序
select * from dept order by nlssort(name,'NLS_SORT=SCHINESE_STROKE_M');
按照部首排序
select * from dept order by nlssort(name,'NLS_SORT=SCHINESE_RADICAL_M');
按照拼音排序,此为系统的默认排序方式
select * from dept order by nlssort(name,'NLS_SORT=SCHINESE_PINYIN_M');
4、修改系统参数(数据库所在操作系统):
set NLS_SORT=SCHINESE_RADICAL_M ;export NLS_SORT (sh)
setenv NLS_SORT SCHINESE_RADICAL_M (csh)
HKLC\SOFTWARE\ORACLE\home0\NLS_SORT (win注册表)
Oracle 官方说明
NLS_SORT NLS_SORT specifies the collating sequence for ORDER BY queries. NLS_COMP NLS_COMP specifies the collation behavior of the database session.
Property | Description |
Parameter type | String |
Syntax | NLS_SORT = { BINARY | linguistic_definition } |
Default value | Derived from NLS_LANGUAGE |
Modifiable | ALTER SESSION |
Range of values | BINARY or any valid linguistic definition name |
- If the value is BINARY, then the collating sequence for ORDER BY queries is based on the numeric value of characters (a binary sort that requires less system overhead).
-
If the value is a named linguistic sort, sorting is based on the order of the defined linguistic sort. Most (but not all) languages supported by the NLS_LANGUAGE parameter also support a linguistic sort with the same name.
Note:
Setting NLS_SORT to anything other than BINARY causes a sort to use a full table scan, regardless of the path chosen by the optimizer. BINARY is the exception because indexes are built according to a binary order of keys. Thus the optimizer can use an index to satisfy the ORDER BY clause when NLS_SORT is set to BINARY. If NLS_SORT is set to any linguistic sort, the optimizer must include a full table scan and a full sort in the execution plan.
You must use the NLS_SORT operator with comparison operations if you want the linguistic sort behavior.
Property | Description |
Parameter type | String |
Syntax | NLS_COMP = { BINARY | LINGUISTIC | ANSI } |
Default value | BINARY |
Modifiable | ALTER SESSION |
Basic | No |
Values:
Normally, comparisons in the WHERE clause and in PL/SQL blocks is binary unless you specify the NLSSORT function.
Comparisons for all SQL operations in the WHERE clause and in PL/SQL blocks should use the linguistic sort specified in the NLS_SORT parameter. To improve the performance, you can also define a linguistic index on the column for which you want linguistic comparisons.
A setting of ANSI is for backwards compatibility; in general, you should set NLS_COMP to LINGUISTIC
文章来源:
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