如何像在SQL中一样对文本进行计数?
如何像在SQL中一样对文本进行计数如何像在SQL中一样对文本进行计数?,sql,tsql,Sql,Tsql,如何像在SQL中一样对文本进行计数 IF OBJECT_ID('tempdb..#t') IS NOT NULL DROP TABLE #t Create table #t (message nvarchar(4000), messagedate datetime) insert into #t values ('Column Listing have data error', getdate()) WAITFOR DELAY '00:00:00:02'; insert into #
IF OBJECT_ID('tempdb..#t') IS NOT NULL
DROP TABLE #t
Create table #t (message nvarchar(4000), messagedate datetime)
insert into #t values ('Column Listing have data error', getdate())
WAITFOR DELAY '00:00:00:02';
insert into #t values ('Column Listing have name error', getdate())
WAITFOR DELAY '00:00:00:02';
insert into #t values ('Column Listing have city error', getdate())
select * from #t
select count(message like 'column%') , max(messagedate) from #t
group by message
将逻辑部分放入子查询中,然后只在主查询中计数 选择Message,COUNTMessage作为MessageCount,MAXMessageDate作为MAXMessageDate 从SELECT Message,messagedate FROM t,其中的消息类似于'column%'a
使用条件聚合按消息分组,但我看不出应该在哪里使用分组:
select
sum(case when message like 'column%' then 1 else 0 end) counter,
max(messagedate) maxdate
from #t
如果您还希望仅为类似“column%”的邮件指定最大日期,请执行以下操作:
select
count(*) counter,
max(messagedate) maxdate
from #t
where message like 'column%'
看。
结果:
> counter | maxdate
> ------: | :------------------
> 3 | 16/04/2019 16:50:25