NLS_SORT设置

Oracle数据库中文拼音排序问题，NLS_SORT设置

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

BINARY_CI 忽略大小写的排序

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 = SCHINESE_RADICAL_M；

忽略大小写：alter session set nls_sort = BINARY_CI；

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');

忽略大小写 

select * from dept order by nlssort(name,'NLS_SORT=BINARY_CI');

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)

5、设置查询时忽略大小写方法：

alter session set nls_sort='BINARY_CI';

alter session set nls_comp='LINGUISTIC';

 

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:

• BINARY

Normally, comparisons in the WHERE clause and in PL/SQL blocks is binary unless you specify the NLSSORT function.

• LINGUISTIC

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.

• ANSI

A setting of ANSI is for backwards compatibility; in general, you should set NLS_COMP to LINGUISTIC

 

符合NLS_SORT所有的值请在v$nls_valid_values视图中找