如果在数据库中,直接一条SQL语句就能查出来吧能问下,SQL 语句如何写? 表 Table A 字段 datetime a1, double a2
select top 1 * from tb order by timestamp 比较最大值 select * from Tb a where cast([value] as int)=[value] not exists(selcet 1 FROM Tb WHERE cast([value] as int)=[value] and is=a.id and a.timestamp<[timestamp] )
int[] array = { 1,2,3,4}; for (int i = 1; i < array.Length; i++)
{
if (array[i] < array[i - 1])
throw new Exception();
}
[timestamp] [datetime] NOT NULL,
[data] [int] NOT NULL,
CONSTRAINT [PK_datatable] PRIMARY KEY CLUSTERED
(
[timestamp] ASC
)WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]
用以下语句获取结果集SELECT [timestamp],[data]
FROM [master].[dbo].[datatable]
ORDER BY timestamp
在程序中获取到结果集放到DATASET中,例如是ds
遍历ds比较相邻两个值的大小,如果后面的值比前面小,则返回false,return
一开始俺的思路也是这样的,但是循环比较实在是效率太低了。而且通常情形下,数据量很大。能有些更好的、效率高些的建议吗?
你这一列是存储在什么数据结构里?如果在数据库中,直接一条SQL语句就能查出来吧
字段 datetime a1, double a2
select * from Tb a
where cast([value] as int)=[value]
not exists(selcet 1 FROM Tb WHERE cast([value] as int)=[value] and
is=a.id and a.timestamp<[timestamp] )