mysql 常用查詢模型

1.乙個欄位有多個可取值，先要統計每個可取值數量

demo1 統計從 常駐/流動人口

-- 統計常駐人口、流動人口

-- migration_type 人口流動 (1:常住;2:常訪客;3:臨時訪客)
select sum(mobile) as mobile,sum(permanent) as permanent
from
(select 
case when migration_type='1'  then 1 else 0 end mobile ,
case when migration_type in('2','3')  then 1 else 0 end permanent
from sys_staff_info where domain = 'default') tmp

-- 分別統計統計獨居老人、養犬人員、五保戶、重點關注人群、其他

-- people_type 人群型別（0:正常;1:獨居老人;2:養犬人員;3:五保戶;4:疆藏;5:精神病;6:刑滿釋放;7:社群矯正;8:吸毒人員;9:上訪人員）
select sum(olderly_alone) as olderly_alone,sum(dog_keeeper) as dog_keeeper,
sum(low_salary) as low_salary,sum(focus_crowd) as focus_crowd,sum(others) as others
from
(select 
case when people_type='1'  then 1 else 0 end olderly_alone,
case when people_type='2'  then 1 else 0 end dog_keeeper,
case when people_type='3'  then 1 else 0 end low_salary,
case when people_type in('4','5','6','7','8','9')  then 1 else 0 end focus_crowd,
case when people_type in('0','')  then 1 else 0 end others
from sys_staff_info where domain = 'default') tmp

-- 統計疫情級別

-- country 國籍(0:中國;1:外國)  sys_city 0:低;1:中;2:高
select sum(low) as low, sum(middle) as middle, sum(high) as high, sum(alien) as alien from (
select case when (tb.level is null or  tb.level = '0') and ta.country = '0' then 1 else 0 end low,
case when tb.level = '1' and ta.country = '0' then 1 else 0 end middle,
case when tb.level = '2' and ta.country = '0' then 1 else 0 end high,
case when ta.country = '1' then 1 else 0 end alien
from sys_staff_info ta left join sys_city tb on ta.city = tb.name
where domain = 'default'
) ta

-- uft下中文 能存33個中文字元。如果有空值，最好 not null default ''

desc_info                     varchar(100) not null default '' comment '資料集備註資訊'
--  日期自動更新
updated_time				  datetime not null default current_timestamp on update current_timestamp  comment '更新日期'
-- 多種型別，可以用char(1) 。mysql不支援bool，用char(1) or tinyint

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