Oracle query Character Set, Oracle Character Set

Oracle query Character Set, Oracle Character Set

Select * from nls_database_parameters

Forget it.

How to view the character set of the Oracle database, detailed operations, xx

Database Server Character Set select * from nls_database_parameters, which is derived from props $ and represents the character set of the database.
　　
Client Character Set environment select * from nls_instance_parameters, which is from v $ parameter,
　　
Indicates the character set setting of the client, which may be a parameter file, environment variable, or registry.
　　
Select * from nls_session_parameters in the session Character Set environment, which is derived from v $ nls_parameters, indicating the session's own settings, which may be the session environment variable or the session is completed by alter session. If the session has no special settings, it will be consistent with nls_instance_parameters.
　　
The character set of the client must be the same as that of the server to correctly display non-Ascii characters of the database. If multiple settings exist, alter session> environment variable> registry> parameter file
　　
The character set must be consistent, but the language settings can be different. We recommend that you use English for language settings. If the character set is zhs16gbk, The nls_lang can be American_America.zhs16gbk.

Involves three character sets,
1. Character Set on the El server side;
2. Character Set of oracle client;
3. dmp file character set.

During data import, the three character sets must be consistent before the data can be correctly imported.

2.1 query character sets on oracle server
There are many ways to find the character set of the oracle server. The intuitive query method is as follows:
SQL> select userenv ('language') from dual;
USERENV ('language ')
----------------------------------------------------
SIMPLIFIED CHINESE_CHINA.ZHS16GBK

SQL> select userenv ('language') from dual;
AMERICAN _ AMERICA. ZHS16GBK

2.2 how to query the dmp file Character Set
The dmp file exported using oracle's exp tool also contains character set information. The 2nd and 3rd bytes of the dmp file record the character set of the dmp file. If the dmp file is not large, for example, only a few MB or dozens of MB, you can use UltraEdit to open it (in hexadecimal mode) and view the content of 2nd 3rd bytes, such as 0354, then, use the following SQL statement to find the corresponding character set:
SQL> select nls_charset_name (to_number ('20140901', 'xxxxx') from dual;
ZHS16GBK

If the dmp file is large, for example, 2 GB or above (this is also the most common case), you can use the following command (on a unix host) to open it slowly or completely ):
Cat exp. dmp | od-x | head-1 | awk '{print $2 $3}' | cut-c 3-6
Then, you can use the preceding SQL statement to obtain its character set.

2.3 query character sets of oracle client
On windows, it is the NLS_LANG of OracleHome in the registry. You can also set it in the dos window,
For example: set nls_lang = AMERICAN_AMERICA.ZHS16GBK
In this way, only the environment variables in this window are affected.

On the unix platform, the environment variable NLS _... the remaining full text>

How to change the oracle character set encoding in Windows and Linux?

Select userenv ('language') from dual (client query)
----- View and change the oracle character set encoding in Windows
Open the registry -- HKEY_LOCAL_MACHINE \ SOFTWARE \ ORACLE \ HOMExx \ NLS_LANG
Modify the key value of NLS_LANG
# Common Chinese character sets
Set NLS_LANG = SIMPLIFIED CHINESE_CHINA.ZHS16GBK
# Common unicode character sets
Set NLS_LANG = american_america.AL32UTF8
----- View and change the oracle character set encoding in Linux
[Root @ OracleDB ~] # Cd/usr/local/oracle/
[Root @ OracleDB oracle] # env | grep NLS_LANG
NLS_LANG = american_america.zhs16gbk
[Root @ OracleDB oracle] # vi. bash_profile
# Make the bash_profile settings take effect