如果Confluence MySQL字符集设置的不正确，需要修改字符集为utf8mb4, collation为utf8mb4_bin. 需求修改以下几个方面，

  1. 数据库服务器参数修改（character-set-server=utf8mb4 collation-server=utf8mb4_bin）
  2. 数据库的编码方式及collation，数据库中的表的编码方式和collation，表中每个列的编码方式及collation。
  3. confluence的连接数据库参数（配置文件）

具体操作步骤如下：

1、停止confluence服务。

2、数据库服务器参数修改：

在my.ini文件中增加character-set-server=utf8mb4 collation-server=utf8mb4_bin，然后重启mysql

3、修改数据库、表、字段的字符集和collation


SET FOREIGN_KEY_CHECKS=0;

//To Change database collation
ALTER DATABASE confluencedb CHARACTER SET utf8mb4 COLLATE utf8mb4_bin;


//To change table collation:
SELECT CONCAT('ALTER TABLE `',  table_name, '` CHARACTER SET utf8mb4 COLLATE utf8mb4_bin;')
FROM information_schema.TABLES AS T, information_schema.`COLLATION_CHARACTER_SET_APPLICABILITY` AS C
WHERE C.collation_name = T.table_collation
AND T.table_schema = 'confluencedb'
AND
(
    C.CHARACTER_SET_NAME != 'utf8mb4'
    OR
    C.COLLATION_NAME != 'utf8mb4_bin'
);


//To change column collation for varchar columns:
SELECT CONCAT('ALTER TABLE `', table_name, '` MODIFY `', column_name, '` ', DATA_TYPE, '(', CHARACTER_MAXIMUM_LENGTH, ') CHARACTER SET utf8mb4 COLLATE utf8mb4_bin', (CASE WHEN IS_NULLABLE = 'NO' THEN ' NOT NULL' ELSE '' END), ';')
FROM information_schema.COLUMNS 
WHERE TABLE_SCHEMA = 'confluencedb'
AND DATA_TYPE = 'varchar'
AND
(
    CHARACTER_SET_NAME != 'utf8mb4'
    OR
    COLLATION_NAME != 'utf8mb4_bin'
);

//To change column collation for non-varchar columns:
SELECT CONCAT('ALTER TABLE `', table_name, '` MODIFY `', column_name, '` ', DATA_TYPE, ' CHARACTER SET utf8mb4 COLLATE utf8mb4_bin', (CASE WHEN IS_NULLABLE = 'NO' THEN ' NOT NULL' ELSE '' END), ';')
FROM information_schema.COLUMNS 
WHERE TABLE_SCHEMA = 'confluencedb'
AND DATA_TYPE != 'varchar'
AND
(
    CHARACTER_SET_NAME != 'utf8mb4'
    OR
    COLLATION_NAME != 'utf8mb4_bin'
);

SET FOREIGN_KEY_CHECKS=1;
SQL

4、如果mysql服务器不能更改字符集（因为没有权限或者还有别的数据库共享同一个mysql实例）可以如下配置confluence数据库连接：

编辑文件： <Confluence-home>/confluence.cfg.xml  

更新此属性：

<property name="hibernate.connection.url">jdbc:mysql://yourhost:3306/confluence?connectionCollation=utf8mb4_bin</property>
CODE

5、启动Confluence