我将数据库转换为utf8字符集和utf8_unicode_ci整理。当将表的字符集更改为utf8时，MySQL会自动将表的列转换为utf8：utf_general_ci的默认排序规则。我不想运行数百个alter column命令将每个列转换为utf8_unicode_ci，因此我可以将utf8的默认排序规则设置为utf8_unicode_ci，如information_schema？中所示：
SELECT * FROM information_schema.COLLATIONS WHERE CHARACTER_SET_NAME = 'utf8';
+---------------------------+--------------------+-----+------------+-------------+---------+
| COLLATION_NAME | CHARACTER_SET_NAME | ID | IS_DEFAULT | IS_COMPILED | SORTLEN |
+---------------------------+--------------------+-----+------------+-------------+---------+
| utf8_general_ci | utf8 | 33 | Yes | Yes | 1 |
| utf8_bin | utf8 | 83 | | Yes | 1 |
| utf8_unicode_ci | utf8 | 192 | | Yes | 8 |
| utf8_icelandic_ci | utf8 | 193 | | Yes | 8 |
| utf8_latvian_ci | utf8 | 194 | | Yes | 8 |
| utf8_romanian_ci | utf8 | 195 | | Yes | 8 |
| utf8_slovenian_ci | utf8 | 196 | | Yes | 8 |
| utf8_polish_ci | utf8 | 197 | | Yes | 8 |
| utf8_estonian_ci | utf8 | 198 | | Yes | 8 |
| utf8_spanish_ci | utf8 | 199 | | Yes | 8 |
| utf8_swedish_ci | utf8 | 200 | | Yes | 8 |
| utf8_turkish_ci | utf8 | 201 | | Yes | 8 |
| utf8_czech_ci | utf8 | 202 | | Yes | 8 |
| utf8_danish_ci | utf8 | 203 | | Yes | 8 |
| utf8_lithuanian_ci | utf8 | 204 | | Yes | 8 |
| utf8_slovak_ci | utf8 | 205 | | Yes | 8 |
| utf8_spanish2_ci | utf8 | 206 | | Yes | 8 |
| utf8_roman_ci | utf8 | 207 | | Yes | 8 |
| utf8_persian_ci | utf8 | 208 | | Yes | 8 |
| utf8_esperanto_ci | utf8 | 209 | | Yes | 8 |
| utf8_hungarian_ci | utf8 | 210 | | Yes | 8 |
| utf8_sinhala_ci | utf8 | 211 | | Yes | 8 |
| utf8_german2_ci | utf8 | 212 | | Yes | 8 |
| utf8_croatian_mysql561_ci | utf8 | 213 | | Yes | 8 |
| utf8_unicode_520_ci | utf8 | 214 | | Yes | 8 |
| utf8_vietnamese_ci | utf8 | 215 | | Yes | 8 |
| utf8_general_mysql500_ci | utf8 | 223 | | Yes | 1 |
| utf8_croatian_ci | utf8 | 576 | | Yes | 8 |
| utf8_myanmar_ci | utf8 | 577 | | Yes | 8 |
+---------------------------+--------------------+-----+------------+-------------+---------+
请注意IS_DEFAULT列。
另请注意，我并未询问如何使用ALTER转换数据库，表格或列！
此外，将collation_server = utf8_unicode_ci添加到my.cnf无效。
答案 0 :(得分：1)
每个表需要一个ALTER，而不是每列Reference）：
ALTER TABLE foo CONVERT TO CHARACTER SET utf8 COLLATE utf8_unicode_ci;
您可以生成所有更改，然后手动复制它们以执行它们。像
这样的东西SELECT CONCAT("ALTER TABLE ", table_schema, ".", table_name,
" CONVERT TO CHARACTER SET utf8 COLLATE utf8_unicode_ci;
")
FROM information_schema.tables
WHERE table_schema NOT IN ('mysql', 'information_schema',
'performance_schema', 'sys_schema');
但我建议你CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_520_ci这样你就可以处理所有中文，加上表情符号。
我希望你做过CONVERT TO，而不只是MODIFY COLUMN。前者转换人物;后者将使表中已有的任何8位字符混乱。
如果您在VARCHAR(255)上有索引，则会发生utf8mb4的问题。如果可行，将尺寸缩小到191或更小。
示例
mysql> SHOW CREATE TABLE iidr\G
*************************** 1. row ***************************
Table: iidr
Create Table: CREATE TABLE `iidr` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`key2` int(10) unsigned NOT NULL,
`vc` varchar(99) DEFAULT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `key2` (`key2`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8
1 row in set (0.00 sec)
mysql> SHOW FULL COLUMNS FROM iidr;
+-------+------------------+-----------------+------+-----+---------+----------------+---------------------------------+---------+
| Field | Type | Collation | Null | Key | Default | Extra | Privileges | Comment |
+-------+------------------+-----------------+------+-----+---------+----------------+---------------------------------+---------+
| id | int(10) unsigned | NULL | NO | PRI | NULL | auto_increment | select,insert,update,references | |
| key2 | int(10) unsigned | NULL | NO | UNI | NULL | | select,insert,update,references | |
| vc | varchar(99) | utf8_general_ci | YES | | NULL | | select,insert,update,references | |
+-------+------------------+-----------------+------+-----+---------+----------------+---------------------------------+---------+
3 rows in set (0.00 sec)
mysql> ALTER TABLE iidr CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_520_ci;
Query OK, 2 rows affected (0.14 sec)
Records: 2 Duplicates: 0 Warnings: 0
mysql> SHOW FULL COLUMNS FROM iidr;
+-------+------------------+------------------------+------+-----+---------+----------------+---------------------------------+---------+
| Field | Type | Collation | Null | Key | Default | Extra | Privileges | Comment |
+-------+------------------+------------------------+------+-----+---------+----------------+---------------------------------+---------+
| id | int(10) unsigned | NULL | NO | PRI | NULL | auto_increment | select,insert,update,references | |
| key2 | int(10) unsigned | NULL | NO | UNI | NULL | | select,insert,update,references | |
| vc | varchar(99) | utf8mb4_unicode_520_ci | YES | | NULL | | select,insert,update,references | |
+-------+------------------+------------------------+------+-----+---------+----------------+---------------------------------+---------+
3 rows in set (0.00 sec)
mysql> SHOW CREATE TABLE iidr\G
*************************** 1. row ***************************
Table: iidr
Create Table: CREATE TABLE `iidr` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`key2` int(10) unsigned NOT NULL,
`vc` varchar(99) COLLATE utf8mb4_unicode_520_ci DEFAULT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `key2` (`key2`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_520_ci
1 row in set (0.00 sec)
答案 1 :(得分：0)
我建议您使用所需的排序规则创建数据库并运行脚本来复制所有表和数据（在登台服务器中，我建议您在登台服务器中执行此操作不在PROD中），检查暂存是否一切正常，然后在PROD中进行。