How to convert oracle character set

Oracle character set conversion is a relatively common requirement. It is usually applied when different regions or countries use different character sets. In this case, Oracle Database needs to convert the data from one character set to another to ensure the correctness and integrity of the data. In this article, we will discuss the basics of Oracle character set conversion, including the concept of character sets, why character set conversion is needed, common character set conversion methods, and specific operations on how to perform character set conversion.

1. The concept of character set

Character set refers to a specific character encoding scheme, which is used to map characters into numerical sequences so that computers can understand and process them. Different character sets support different character sets. These character sets include letters, numbers, symbols, Chinese characters, etc. The characters in each character set are given a unique numerical representation. These numbers are expressed in binary form in the computer. storage.

Oracle database supports many character sets, including ASCII, ISO-8859, GB2312, UTF-8, etc. Different character sets support different character ranges and encoding methods. In Oracle database, each database instance has a default character set. We can query the NLS_CHARACTERSET parameter to view the default character set of the current database instance.

2. Why character set conversion is needed

Character set conversion exists in Oracle database due to the following reasons:

1. The data in the database comes from different regions or Countries, use different character sets.
2. The application needs to convert data from an Arabic character set to a Latin character set and so on.
3. The database character set needs to be upgraded, and the original character set needs to be converted to a new character set.
4. Carry out data migration and migrate the data in the original database to the new system. The character set of the new system is different from the original character set and needs to be converted.

3. Common character set conversion methods

1. Software method: Export the data file from the source system, and then use the conversion tool to convert the data in the exported data file to Encoding format supported by the target character set.
2. Database method: Use the data migration tool or the character set conversion tool that comes with the database to convert the data in the source database into the character set supported by the target database.

4. Specific operations on how to perform character set conversion

Oracle character set conversion can be easily performed through the NLS_LANG environment variable provided by Oracle. The following are the specific conversion steps:

1. Determine the source character set and target character set.
2. Export the data in the source database through the export command. For example:

$ exp '用户名/密码@数据库名' file=导出文件名

3. Set the NLS_LANG environment variable to the correct character set format. For example:

$ export NLS_LANG=目标字符集格式

4. Use the imp command to import the export file into the target database. For example:

$ imp '用户名/密码@目标数据库名' file=导出文件名

Through the above steps, you can easily complete the character set conversion of Oracle database.

Summary:

The above is the basic knowledge of Oracle character set conversion, why character set conversion is needed, common character set conversion methods, and specific operation methods of character set conversion. In scenarios such as data migration and upgrade, Oracle character set conversion is usually an issue that must be considered. Correct character set conversion can ensure the correctness and integrity of the data and ensure the normal operation of the application.

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