How many Chinese characters can be stored in to_char() in Oracle?

Oracle's TO_CHAR() function can store Chinese characters, the number depends on the character set, character width and data type. In the UTF-8 character set, VARCHAR2 variables can store approximately 1333 Chinese characters, while CLOB variables can store approximately 1.33 million Chinese characters. The amount of storage varies based on character width and content, and Oracle version and configuration also affect capacity.

The TO_CHAR() function in Oracle stores the number of Chinese characters

The TO_CHAR() function in Oracle can convert data is a character representation. It supports storing Chinese characters, but the specific number depends on several factors:

Character set and character width

Oracle uses character sets to store data, and different character sets support Different character widths. For example:

• UTF-8: Up to 4 bytes per character
• AL32UTF8: 4 bytes per character
• ZHS16GBK: 2 per Chinese character Bytes

Data type

TO_CHAR() function can be applied to different data types, such as VARCHAR2 and CLOB:

• VARCHAR2: Use character set to store data, limited length (default 4000 bytes)
• CLOB: Store large text objects, up to 4 GB in length

Example

In the following example, we use the TO_CHAR() function to store Chinese characters in the VARCHAR2 and CLOB data types of the UTF-8 character set:

<code>-- VARCHAR2
SET NLS_CHARACTERSET = 'UTF8';
DECLARE v_str VARCHAR2(4000) := '这是汉字示例';

-- CLOB
DECLARE c_str CLOB := '这是汉字示例';</code>

In the UTF-8 character set, each Chinese characters occupy 3 bytes. Therefore, the above VARCHAR2 variable can store approximately 1333 Chinese characters (4000 bytes / 3 bytes / Chinese character). CLOB variables can theoretically store approximately 1.33 million Chinese characters (4 GB / 3 bytes / Chinese character).

Note:

• The number of bytes of Chinese characters may vary depending on character width and actual content.
• Oracle version and configuration may also affect storage capacity.

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