以下语句为什么查不到数据:
select slm,substr(id,1,5) lb,count(*) wjsnum from wscl_wsda_file
join xtwh_struct_class on dh like '''+substr(id,1,5)%+'''
where length(slh)>=4 and wjnd='2004' group by slm,substr(id,1,5) order by slm;以上语句正确吗?
select slm,substr(id,1,5) lb,count(*) wjsnum from wscl_wsda_file
join xtwh_struct_class on dh like '''+substr(id,1,5)%+'''
where length(slh)>=4 and wjnd='2004' group by slm,substr(id,1,5) order by slm;以上语句正确吗?
like substr(id,1,5)+'%'
from
(
select 'abcdef' a from dual
) where a like substr('abcdef',1,3)||'%'
--result:
abcdef