MySQL error: specified key was too long; max key length is 767 bytes

In execution mysql Script time , Report errors ：Specified key was too long; max key length is 767 bytes.

terms of settlement ：

mysql The character set of is utf8mb4

1、 First check that the database is limited in the size of the index
SHOW variables like 'innodb_large_prefix';
If the value of the query is off Words , Execute the following command
SET GLOBAL INNODB_LARGE_PREFIX = ON;
2、 performed , You also need to view the current innodb_file_format Is the engine format type BARRACUDA
SHOW variables like ‘innodb_file_format’;
If not, it needs to be modified
SET GLOBAL innodb_file_format = BARRACUDA;