MYSQL中的utf8mb4(Unicode Transformation Format 8-bit MultiByte 4-byte)_character set utf8mb4

Simply put

In MySQL, the UTF8MB4 character set is an extension of the UTF8 character set. It allows you to store and handle a wider range of Unicode characters, including emojis and characters from various scripts and languages.

The “UTF8MB4” name itself indicates the following:

• “UTF8”: It refers to the Unicode Transformation Format 8-bit, which is a variable-length character encoding capable of representing all Unicode characters.
• “MB4”: It stands for “MultiByte 4-byte,” indicating that this character set can handle characters that require up to 4 bytes for encoding.

To use the UTF8MB4 encoding in MySQL, you need to ensure the following:

1. Character Set: Set the character set of the database, table, and columns to “utf8mb4”. For example, when creating a table:

CREATE TABLE your_table (
    column1 VARCHAR(50) CHARACTER SET utf8mb4,
    column2 TEXT CHARACTER SET utf8mb4,
    ...
) DEFAULT CHARACTER SET utf8mb4;
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2. Connection Encoding: Set the connection encoding to “utf8mb4” to ensure that data is correctly encoded and decoded when interacting with the database. You can do this by executing the following query after establishing a connection:

SET NAMES utf8mb4;
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By using the UTF8MB4 encoding, you can store and manipulate a wide range of characters in your MySQL database, making it suitable for applications that require support for diverse languages and symbols.

说明

MySQL中的utf8mb4是一种字符集，它支持存储Unicode字符集中的所有字符，包括一些表情符号和其他特殊字符，这些字符在早期的utf8字符集中无法支持。utf8mb4是MySQL 5.5.3及更高版本的默认字符集。

utf8mb4与utf8的差异在于，utf8只支持存储Unicode字符集中的最大3字节字符，而utf8mb4则支持存储最大4字节字符，即能够存储更多的特殊字符。因此，在存储需要支持特殊字符的数据时，需要使用utf8mb4字符集。

需要注意的是，使用utf8mb4字符集存储数据时，一个字符可能占用多个字节，因此需要注意存储和检索的长度限制。同时，在一些旧的应用程序或库中，可能不支持utf8mb4字符集，因此需要进行兼容性测试和适当的字符集转换。