How to set encoding in oracle

In Oracle database, character set is a very important part. Character sets determine how the database handles different characters, data types, and languages. In some cases, especially when working in Oracle multinationals or in multi-language environments, setting the appropriate character set is critical.

Oracle supports many different character sets and languages, including Unicode and many single-byte and multi-byte character sets. By default, Oracle database uses the operating system character set, which may not be the best choice. In this article, we will discuss how to properly set up Oracle's character set to ensure that your database can handle a variety of languages ​​and character sets.

Step 1: Determine the current character set

To view the current character set of the Oracle database, run the following command:

SELECT * FROM nls_database_parameters WHERE parameter like '%CHARACTERSET';

This command will display the current character set of the database set up. Normally, Oracle uses the operating system's character set by default, such as ISO-8859-1, but this is not necessarily the best character set. If you need to handle many different characters and languages, you may need to change this setting.

Step Two: Choose the Right Character Set

When choosing a character set, it is important to consider what types of data your application needs to handle. If your application needs to handle different languages ​​and character sets, it is better to choose a Unicode character set such as UTF-8 or UTF-16. These character sets support languages ​​from around the world, including Western languages, Chinese, and Arabic, among others.

In addition, the space limitations of the database need to be considered when selecting the character set. Certain character sets require more space to store data, which can affect query performance and data storage.

Step 3: Set a new character set

To change the character set of the Oracle database, you need to run a series of commands. First, you need to stop the Oracle database instance:

SQL> SHUTDOWN IMMEDIATE;

Then, you need to modify the Oracle parameter file, often called SPFILE or PFILE, to include the new character set settings. To edit the Oracle parameter file, use the following command:

SQL> CREATE SPFILE FROM PFILE;
SQL> CONNECT / AS SYSDBA;
SQL> ALTER SYSTEM SET NLS_CHARACTERSET = '新字符集' SCOPE=SPFILE;

Here, replace "New Character Set" with the character set name of your choice. For example, if you wanted to change the character set to UTF-8, this command would look like this:

SQL> ALTER SYSTEM SET NLS_CHARACTERSET = 'UTF8' SCOPE=SPFILE;

Finally, you need to restart the Oracle database instance for the changes to take effect:

SQL> STARTUP;

Now you have successfully changed Oracle's character set settings.

Conclusion

When using Oracle database in a multinational company or multi-language environment, it is very important to set the correct character set. Properly selecting and setting character sets ensures that your database can handle a variety of languages ​​and character sets and improves query performance and data storage. By following the steps mentioned in this article, you can easily change the character set settings of your Oracle database.

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