set @address='中国-山东省-聊城市-莘县';
select @address

select length('a')
,char_length('a')
,length('中')
,char_length('中')

set @address='中国-山东省-聊城市-莘县';
select @address
,replace(@address,'-','') as address_1
,length(@address) as len_add1
,length(replace(@address,'-','')) as len_add2
,length(@address)-length(replace(@address,'-','')) as _count

select max(length(com_industry)-length(replace(com_industry,'-',''))) as _max_count
from etl1_socom_data

set @address='中国-山东省-聊城市-莘县';
select 
substring_index(@address,'-',1) as china,
substring_index(substring_index(@address,'-',2),'-',-1) as province,
substring_index(substring_index(@address,'-',3),'-',-1) as city,
substring_index(@address,'-',-1) as district

case when then when then else 值 end as 字段名

select case when 89>101 then '大于' else '小于' end as betl1_socom_data

select a.*,
case when com_district like '%业' or com_district like '%织' or com_district like '%育' then null else com_district end as com_district1
,case when com_district like '%业' or com_district like '%织' or com_district like '%育' then concat(com_district,'-',com_industry) else com_industry end as com_industry_total
,replace(com_addr,'地 址：','') as com_addr1
,replace(com_phone,'电 话：','') as com_phone1
,replace(com_fax,'传 真：','') as com_fax1
,replace(com_mobile,'手机：','') as com_mobile1
,replace(com_url,'网址：','') as com_url1
,replace(com_email,'邮箱：','') as com_email1
,replace(com_contactor,'联系人：','') as com_contactor1
,replace(com_emploies_nums,'公司人数：','') as com_emploies_nums1
,replace(com_reg_capital,'注册资金：万','') as com_reg_capital1
,replace(com_type,'经济类型：','') as com_type1
,replace(com_product,'公司产品：','') as com_product1
,replace(com_desc,'公司简介：','') as com_desc1
from s_socom_data as a

select a.*,
case 
#行业为''的值 置为空
when length(com_industry)=0 then null
#其他的取第一个-分隔符之前
else substring_index(com_industry,'-',1) end as com_industry1,
case 
when length(com_industry)-length(replace(com_industry,'-',''))=0 then null
#'交通运输、仓储和邮政业-' 这种值 行业2 也置为null
when length(com_industry)-length(replace(com_industry,'-',''))=1 and length(substring_index(com_industry,'-',-1))=0 then null
when length(com_industry)-length(replace(com_industry,'-',''))=1 then substring_index(com_industry,'-',-1)
else substring_index(substring_index(com_industry,'-',2),'-',-1)
end as com_industry2,
case 
when length(com_industry)-length(replace(com_industry,'-',''))<=1 then null
when length(com_industry)-length(replace(com_industry,'-',''))=2 then substring_index(com_industry,'-',-1)
else substring_index(substring_index(com_industry,'-',3),'-',-1)
end as com_industry3,
case 
when length(com_industry)-length(replace(com_industry,'-',''))<=2 then null
else substring_index(com_industry,'-',-1)
end as com_industry4
from etl1_socom_data as a

select count(1) from s_socom_data
union all
select count(1) from etl1_socom_data
union all
select count(1) from etl2_socom_data

select * 
from etl2_socom_data 
where com_district is null and length(com_industry)-length(replace(com_industry,'-',''))=3