Specified key was too long; max key length is 767 bytes mysql

Specified key was too long; max key length is 767 bytes

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异常详细信息: MySql.Data.MySqlClient.MySqlException: Specified key was too long; max key length is 767 bytes

给Context增加如下的注解

[DbConfigurationType(typeof(MySql.Data.Entity.MySqlEFConfiguration))]
public class MyContext : DbContext
{ 
}