MySQL参数之lower_case_table_names

lower_case_table_names 参数MySQL 库表 大小写，默认为0
0 库表敏感，区分大小写，指定的大小写保存文件
1 库表不敏感，不区分大小写，文件系统以小写保存
2 使用Create语句指定的大小写保存文件，但MySQL会将之转化为小写,启动的时候日志报警告

参数从0调为1
lower_case_table_names =0下操作库表都敏感

mysql> create  database wx;Query OK, 1 row affected (0.01 sec)mysql> create  database WX;Query OK, 1 row affected (0.00 sec)mysql> use wx;Database changedmysql> show tables;Empty set (0.00 sec)mysql> create table wx(id int);Query OK, 0 rows affected (0.01 sec)mysql> create table WX(id int);Query OK, 0 rows affected (0.01 sec)

调整参数lower_case_table_names =1
此时：两表都有表信息，现在虽然有两库，但是在一库中建立表，另一库中也会出现表

mysql> use wx;Reading table information for completion of table and column namesYou can turn off this feature to get a quicker startup with -ADatabase changedmysql> show tables;+--------------+| Tables_in_wx |+--------------+| WX           || wx           |+--------------+2 rows in set (0.00 sec)mysql> use WX;Reading table information for completion of table and column namesYou can turn off this feature to get a quicker startup with -ADatabase changedmysql> show tables;+--------------+| Tables_in_wx |+--------------+| WX           || wx           |+--------------+2 rows in set (0.00 sec)

参数lower_case_table_names =1下操作

mysql> create database ww;Query OK, 1 row affected (0.01 sec)mysql> create database WW;ERROR 1007 (HY000): Can't create database 'ww'; database existsmysql> use ww;Database changedmysql> create table ww(id  int);Query OK, 0 rows affected (0.01 sec)mysql> create table WW(id  int);ERROR 1050 (42S01): Table 'ww' already exists

参数从0调到1，变化数据文件仅仅存放在小写的库中

[root@wxtest WX]# lsdb.opt[root@wxtest wx]# lsdb.opt  t1.frm  t1.ibd  wx.frm  WX.frm  wx.ibd  WX.ibd