mysql默认字段值区分大小写：

character-set-server=utf8

collation-server=utf8_bin

init-connect='SET NAMES utf8;'

SELECT DEFAULT_CHARACTER_SET_NAME 'charset', DEFAULT_COLLATION_NAME 'collation'

FROM information_schema.SCHEMATA WHERE SCHEMA_NAME = 'billing01';

SELECT DEFAULT_CHARACTER_SET_NAME 'charset', DEFAULT_COLLATION_NAME 'collation' ,SCHEMA_NAME

FROM information_schema.SCHEMATA;

mysql> SHOW CHARACTER SET LIKE 'utf8';

+---------+---------------+-------------------+--------+

| Charset | Description | Default collation | Maxlen |

+---------+---------------+-------------------+--------+

| utf8 | UTF-8 Unicode | utf8_general_ci | 3 |

+---------+---------------+-------------------+--------+

1 row in set (0.00 sec)

https://blog.csdn.net/ghosind/article/details/83692869

mysql启动报错：

2019-10-29T08:52:41.945012+08:00 0 [ERROR] [MY-010936] [Server] COLLATION 'utf8_bin' is not valid for CHARACTER SET 'utf8mb4'

2019-10-29T08:52:41.946520+08:00 0 [ERROR] [MY-010119] [Server] Aborting

必须加character-set-server=utf8

my.cnf加

init_connect='SET collation_connection = utf8_bin'

也不行。

SHOW CHARACTER SET LIKE 'utf8';

mysqld —-character-set-server=utf8mb4 —-collation-server=utf8mb4_bin

ALTER DATABASE database-name CHARACTER SET charset-name COLLATE collation-name;

ALTER DATABASE billing01 CHARACTER SET utf8 COLLATE utf8_bin;

ALTER DATABASE billing02 CHARACTER SET utf8 COLLATE utf8_bin;

ALTER DATABASE billing03 CHARACTER SET utf8 COLLATE utf8_bin;

ALTER DATABASE billing04 CHARACTER SET utf8 COLLATE utf8_bin;

https://www.cnblogs.com/benpao/p/11519029.html