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Oracle9i之前,中文是按照二進制編碼進行排序的。在oracle9i中新增了按照拼音、部首、筆畫排序功能。

1、設置NLS_SORT參數值
????? SCHINESE_RADICAL_M 按照部首(第一順序)、筆劃(第二順序)排序
????? SCHINESE_STROKE_M 按照筆劃(第一順序)、部首(第二順序)排序
????? SCHINESE_PINYIN_M 按照拼音排序

2、Session級別的設置,修改ORACLE字段的默認排序方式:
????? 按拼音:alter session set nls_sort = SCHINESE_PINYIN_M;
????? 按筆畫:alter session set nls_sort = SCHINESE_STROKE_M;
????? 按偏旁:alter session set nls_sort = NLS_SORT=SCHINESE_RADICAL_M;

3、語句級別設置排序方式:
????? 按照筆劃排序
????? 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,此為系統的默認排序方式
????? select * from dept order by nlssort(name,'NLS_SORT=SCHINESE_PINYIN_M');

4、修改系統參數(數據庫所在操作系統):
????? set NLS_SORT=SCHINESE_RADICAL_M ;export NLS_SORT (sh)
?????? setenv NLS_SORT SCHINESE_RADICAL_M (csh)
????? HKLC\SOFTWARE\ORACLE\home0\NLS_SORT (win注冊表)

Oracle 官方說明

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

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  • 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

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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


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