mysql -- 大小写配置

• 表名大小写配置
• • mysql表名默认区分大小写
  • 修改表名不区分大小写
• 字段大小写配置
• • mysql字段默认不区分大小写
  • 修改字段区分大小写

# 表名小写查询
mysql> select * from big_data where name = 'test999999';
+---------+------------+------+--------------------+
| id      | name       | age  | email              |
+---------+------------+------+--------------------+
| 1000000 | test999999 |    9 | test999999@163.com |
+---------+------------+------+--------------------+
1 row in set (0.00 sec)

# 表名大写查询
mysql> select * from BIG_data where name = 'test999999';
ERROR 1146 (42S02): Table 'test.BIG_data' doesn't exist

• 查看配置

mysql> show global variables like '%lower_case%';
+------------------------+-------+
| Variable_name          | Value |
+------------------------+-------+
| lower_case_file_system | OFF   |
| lower_case_table_names | 0     |
+------------------------+-------+

• 配置说明

lower_case_file_system：表示当前系统文件是否大小写敏感，只读参数，无法修改

• ON：大小写不敏感
• OFF：大小写敏感

lower_case_table_names：标识存储在磁盘是大小写和是否区分大小写

• 1：小写存储，不区分大小写
• 0：按实际存储，区分大小写
• 2：按实际存储，按小写比较

修改表名不区分大小写

• linux

vim  /etc/mysql/my.cnf
# 添加
lower_case_table_names=1

# 重启mysql即可

• 新建docker mysql

docker run -p 3306:33066 --name mysql -v 
	/home/docker/mysql/conf:/home/docker/mysql/conf.d -v 
	/home/docker/mysql/logs:/home/docker/mysql/logs -v 
	/home/docker/mysql/data:/home/docker/mysql/data -e 
	MYSQL_ROOT_PASSWORD=123456 -d mysql 
	--lower_case_table_names=1

• 修改docker mysql

# 直接修改
docker exec mysql bash -c 'echo "lower_case_table_names=1" >> 
/etc/mysql/my.cnf'

# 复制出来修改再复制回去
docker cp mysql:/etc/mysql/mysql.conf.d/mysqld.cnf .
docker cp mysqld.cnf  mysql:/etc/mysql/my.cnf

# 重启
docker restart mysql

mysql> select * from big_data where name = 'test999999';
+---------+------------+------+--------------------+
| id      | name       | age  | email              |
+---------+------------+------+--------------------+
| 1000000 | test999999 |    9 | test999999@163.com |
+---------+------------+------+--------------------+
1 row in set (0.01 sec)

# 字段大写
mysql> select * from big_data where name = 'Test999999';
+---------+------------+------+--------------------+
| id      | name       | age  | email              |
+---------+------------+------+--------------------+
| 1000000 | test999999 |    9 | test999999@163.com |
+---------+------------+------+--------------------+
1 row in set (0.00 sec)

• 查询时自断签加上binary

select * from big_data where binary name = 'Test999999';

• 修改表字段约束

alter table big_data modify column email varchar(64) binary default null;