Oracle Character Set Conversion

In large database management systems, Oracle databases are beyond review in terms of database management capabilities and security. Chinese enterprises also use many Oracle databases, but the character sets of different Oracle versions bring a lot of trouble to data display, data backup, data conversion, and other practical work.
1. character set parameters
Once a database is created, its character set cannot be changed. Therefore, it is very important to consider which character set to use. The database character set should be a superset of the local character set of the operating system. The character set used by the client to access the database determines which superset to select, that is, the database character set should be the superset of all customer character sets.
The following describes some nls_lang parameters related to character sets:
Nls_lang format: nls_lang = language_territory.charset
There are three components (language, region, and Character Set), each of which controls the NLS subset features. The three components can be combined as needed. For example, the network administrator can download dl.bitscn.com.
American_america.us7scii
Jpanese_japan.ja16euc
Language indicates the language of the server message.
Territory specifies the date and number format of the server.
Charset
You can also define the nls_lang parameter in some subsets:
The default date format of nls_date_format
Default date language of nls_date_language
The nls_numberic_characters decimal character is separated from the component
Nls_currency local currency character
Nls_iso_currency ISO currency character
Nls_sort character sorting Sequence
Ii. Character Set Conversion
1. How to modify the nls_lang parameter:
1) log on to Oracle with the Sys user name.
2) view character set content
SQL> select * from props $;
3) modify the corresponding character subset
SQL> Update props $ set value $ = 'simplified Chinese'
Where name = 'nls _ language ';
4) Submit the ticket;
2. Specific applications of the nls_lang parameter:
1) The server/client mode is used. The character sets at both ends are different.
Modify the client character set:
Win95/Win98: Modify the Registry
HKEY_LOCAL_MACHINE \ SOFTWARE \ oracle \ nls_lang
UNIX: Follow the 1 method to directly go to Oracle for modification.
2) use exp/IMP commands for different character sets
Network Management ujia U. bitscn @ com

Follow the 1 method to modify the character set settings of imp. If it is a Win98/Win95 system, you must also modify the registry. Note: The parameters of the three subsets of nls_lang must be consistent. In addition, if the single-and double-byte character sets are different, you cannot modify the character set for conversion. You can use other methods to perform Oracle database migration without modifying the character set. For example, if the data volume is small, you can use the sqlload command to convert text files and use other database software (such as access and FOXPRO) conversion.