oracle 11g garbled code

In the process of using Oracle 11g database, sometimes you will encounter garbled characters, which may have a certain impact on data processing and use. Therefore, in this article, we will introduce the causes and solutions to the Oracle 11g garbled problem, hoping to help solve related problems.

1. Causes of garbled characters

Oracle 11g garbled characters occur because the character set in the database is different from the client's character set, resulting in characters that cannot be correctly converted into the target during the transmission process. character set, resulting in garbled characters.

In Oracle 11g, there are two very important concepts, namely the database character set and the client character set.

1. Database character set

The database character set refers to the character set used when storing data in the database and is used to encode the data. Commonly used character sets in Oracle 11g include AL32UTF8, UTF8, WE8ISO8859P15, etc. Among them, AL32UTF8 is the character set recommended by Oracle, supports Unicode, and can handle characters in all languages ​​​​in the world.

2. Client character set

The client character set refers to the character set used during communication with the database. It is set by a database client application or an application that connects to the database over a network. In Oracle Client, commonly used character sets include UTF-8, GBK, GB18030, US7ASCII, ZHS16GBK, etc.

When the database character set and the client character set are different, garbled characters are prone to occur.

2. Solution

For users who use Oracle data, once the garbled problem occurs, it will have a considerable impact on daily work. Therefore, we need to solve this problem. Here are several ways to solve the problem of garbled characters.

1. Modify the NLS_LANG parameter

NLS_LANG is a parameter in Oracle Client, used to set the client's character set. Its format is "NLS_LANG=language_region.Character set". For example, NLS_LANG=AMERICAN_AMERICA.AL32UTF8 indicates that the local American English client uses the AL32UTF8 character set.

If garbled characters appear when using Oracle Client, you can modify the NLS_LANG parameter to the database character set in Oracle 11g to solve the garbled character problem. For example, if the AL32UTF8 character set is used in Oracle 11g, you can set the NLS_LANG parameter to "AMERICAN_AMERICA.AL32UTF8".

2. Modify the character set

If the character set is different when storing data in the database, it will also cause garbled characters. In this case, the character set in the database needs to be modified.

Oracle 11g supports modifying the character sets of various objects such as tables, columns, and stored procedures. You can use ALTER TABLE, ALTER VIEW, ALTER SEQUENCE and other commands to achieve this.

When modifying the character set, you need to pay attention to the following points:

(1) Once the character set is modified, it will affect all objects in the database. Therefore, before modifying Relevant data needs to be backed up.

(2) Modifying the character set involves data conversion, which will take a long time, so it should be done during non-peak hours.

(3) After modifying the character set, the related programs need to be recompiled.

3. Use Java program for conversion

In Java program, you can use String.getBytes() and new String() functions for character set conversion. For garbled characters, we can use these functions to convert the character set into the target character set.

For example:

//Read data from Oracle 11g database
ResultSet rs = stmt.executeQuery("SELECT * FROM test");

//Read Take the character set as AL32UTF8
byte[] bytes = rs.getBytes("column_name");

//Use UTF-8 for conversion
String str = new String(bytes, "UTF- 8");

4. Use PL/SQL for conversion

In the Oracle 11g database, character set conversion can be easily performed using PL/SQL. First, you need to create a conversion function to convert the data from the source character set to the target character set.

For example:

CREATE OR REPLACE FUNCTION conv_charset(
sourceVar IN VARCHAR2,
sourceChar IN VARCHAR2,
destChar IN VARCHAR2
) RETURN VARCHAR2
DETERMINISTIC
IS
BEGIN
RETURN CONVERT(sourceVar, sourceChar, destChar);
END conv_charset;

Then, you can use this function to modify the data in the database:

UPDATE table_name
SET column_name = conv_charset(column_name, 'AL32UTF8', 'UTF8')
WHERE ...

In this way, the problem of garbled characters can be quickly solved.

Summary

In the process of using the Oracle 11g database, garbled characters may occur. The main reason is that the database character set and the client character set are different. In order to solve this problem, we can start by modifying the NLS_LANG parameters, modifying the character set, using Java programs and using PL/SQL for character set conversion. By gradually troubleshooting and repairing problems, the accuracy and integrity of the data can be ensured, and subsequent data processing and use can be facilitated.

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