mysql按range分区，再按key子分区，增加分区语句怎么写？？？

[qq_34229856]

create table test (acc char(8), bgn_date char(8),info varchar(100))
PARTITION BY RANGE COLUMNS (bgn_date)
SUBPARTITION BY KEY (acc)
SUBPARTITIONs 32 (
partition P20180507values less than ('20180508'),
partition P20180508 values less than ('20180509')
)

增加20180509分区加子分区，求大神回复！！！

[qq_34229856]

我会了