sql 查询某个条件下多条数据中最新的一条数据或最老的一条数据 test_user表结构如下: 需求:查询李四.王五.李二创建的最初时间或者最新时间 1:查询最初的创建时间: SELECT * FROM( SELECT * FROM test_user ) AS tu WHERE NOT EXISTS ( SELECT * FROM( SELECT * FROM test_user ) AS tu2 WHERE tu2.user_name=tu.user_name AND DATE(tu.tim
using System; using System.Collections.Generic; using System.Diagnostics; using System.Linq; using System.Text; using System.Threading.Tasks; namespace ConsoleApp3 { class Program { static LinkedList<int> sortArrayLink = new LinkedList<int>();
--(正常效果) select l.* from loadCurveSampling l left join Meter m on l.meter_id=m.Meter_ID --聚合当天最大值数据记录 合并查询(聚合效果) select l.* from loadCurveSampling l, (), DT, )='2018-10-29' group by meter_id)b left join Meter m on b.meter_id=m.Meter_ID where l.meter_
declare ) ) --获取表的列名 ,),filename INTO #templist FROM (select cl.name as filename from sys.tables AS tb,sys.columns cl where tb.object_id = cl.object_id and tb.name='book') AS A SELECT @intMinId =MIN(RowID),@intMaxId=MAX(RowID) FROM #templist --这里必须设置
原创:lixx ---从UNWIREDATA 表中查询数据,如果该表中地磁状态发生改变(CARDSTATE)执行插入到MAINTABLE 表中---根据唯一值ERID判断,如果ERID值存在,修改该条数据中的地磁状态属性(CARDSTATE)create or replace trigger tri_dici after update of CARDSTATE ON UNWIREDATA FOR EACH ROW declare V_NUM number;BEGIN ----多次查询时,每次都将
有两个导数据的需求,1.一张表里面每一个订单号可能对应多条数据,每个单号返回时间最早的那条. 2.根据条件查询某个字段并按照逗号,合并在一起. 表类似结构如下: 第一条sql:select c.Id,c.OrderNum, c.CreateTime FROM (select t.*,row_number() over(partition by t.OrderNum order by t.CreateTime ) rn from Payinfo t WHERE t.OrderNum IN('20
group_concat()会计算哪些行属于同一组,将属于同一组的列显示出来,group by指定的列进行分组. 例如: -- 根据物流订单id查询所有物流订单,车源订单,车辆信息(多条数据合并为一条数据,英文逗号隔开) SELECT a.id AS logisOrderId, a.logistics_order_code AS logisOrderCode, a.logis_order_sum_fee AS l