select distinct(supply) from cc_third_sku

sum(if(col='',1,0))

count(col='' or null) #不统计null

select connection_id()

show global variables

show global status

show enginx innodb status

show index from cc_third_proque

show processlist

show status

show global status like 'Created_tmp%';

show global status like 'Open_%'

show master status;

show slave status;

show binary logs;

show variables like "%innodb%";