sql语句统计数目的写法

-- sql统计语句写法
-- 门禁查询  正常 报警  故障
select 
sum(case when value = 0 then 1 else 0 end) as normalNum,
sum(case when value = 1 then 1 else 0 end) as warningNum,
sum(case when value = 2 then 1 else 0 end) as faultNum
from ibms_item_parameter where item_id in(
select id from ibms_item where type = 'MJ'
) and parameter_type = 'BJZT'


-- 门禁查询 开启  关闭
select 
sum(case when value = 1 then 1 else 0 end) as openNum,
sum(case when value = 0 then 1 else 0 end) as closeNum
from ibms_item_parameter where item_id in(
select id from ibms_item where type = 'MJ'
) and parameter_type = 'KGZT'