COLLATION 'utf8_general_ci' is not valid for CHARACTER SET 'utf8mb4'

这个错误通常是因为数据库字符集和排序规则不匹配导致的。在MySQL中，utf8_general_ci排序规则只适用于utf8字符集，而不适用于utf8mb4字符集。

解决办法是将数据库表格的字符集和排序规则修改为utf8mb4_unicode_ci。可以使用以下命令修改：

ALTER TABLE table_name CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

请注意，此操作可能会占用一些时间，具体取决于表格的大小。您应该在执行此操作之前备份您的数据。

相关问题

COLLATION 'utf8_general_ci' is not valid for CHARACTER SET 'utf8mb4'. COLLATION 'utf8_general_ci' is not v ... more

I understand that you're encountering an error message related to collation and character set in MySQL. The error message states that the collation 'utf8_general_ci' is not valid for the character set 'utf8mb4'. This error typically occurs when you try to set a collation that is not compatible with the chosen character set.

To resolve this issue, you need to ensure that the collation you choose is compatible with the character set. In this case, since you are using the 'utf8mb4' character set, you should select a collation that is specifically designed for this character set, such as 'utf8mb4_general_ci'.

To change the collation for a table or column, you can use the `ALTER TABLE` or `ALTER COLUMN` statement respectively. Here's an example:

ALTER TABLE your_table MODIFY your_column VARCHAR(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci;

Make sure to replace 'your_table' and 'your_column' with the actual table and column names in your database.

By setting the correct collation for your character set, you should be able to resolve the error.

[42000][1253] COLLATION 'utf8_general_ci' is not valid for CHARACTER SET 'utf8mb4'. COLLATION 'utf8_general_ci' is not v ... more

你遇到了一个错误，错误信息是：[42000][1253] COLLATION 'utf8_general_ci' is not valid for CHARACTER SET 'utf8mb4'. COLLATION 'utf8_general_ci' is not v ...

这个错误通常是由于数据库的字符集和排序规则（collation）不匹配导致的。在MySQL中，字符集是用来确定存储和处理文本数据的编码方式，而排序规则则决定了文本数据的比较和排序方式。

在这个错误中，你正在尝试使用字符集为utf8mb4的数据库，但排序规则却设置为utf8_general_ci。然而，utf8_general_ci排序规则并不适用于utf8mb4字符集。

要解决这个问题，你可以尝试以下几种方法：

1. 将排序规则修改为适用于utf8mb4字符集的规则，比如utf8mb4_general_ci。
2. 将数据库的字符集修改为适用于utf8_general_ci排序规则的字符集，比如utf8。
3. 如果你的应用程序需要支持特定的字符集和排序规则，你可以考虑升级数据库或选择支持你所需字符集和排序规则的数据库。

请注意，在修改数据库的字符集和排序规则之前，一定要备份你的数据以防止意外删除或损坏。此外，如果你不确定如何正确设置字符集和排序规则，请咨询数据库管理员或相关文档以获取准确的指导。