ALTER DATABASE
ALTER DATABASE is used to specify or modify the default character set and collation of the current database. ALTER SCHEMA has the same effect as ALTER DATABASE.
Examples
ALTER {DATABASE | SCHEMA} [db_name]
alter_specification ...
alter_specification:
[DEFAULT] CHARACTER SET [=] charset_name
| [DEFAULT] COLLATE [=] collation_name
The alter_specification option specifies the CHARACTER SET and COLLATE of a specified database. Currently, TiDB only supports some character sets and collations. See Character Set Support for details.
MySQL compatibility
This statement is understood to be fully compatible with MySQL. Any compatibility differences should be reported via an issue on GitHub.