今天正好遇到需要做这个功能,顺手搜了一下网络,把几种方法都列出来,方便以后参考. 1 什么是合并多行字符串(连接字符串)呢,例如: SQL> desc test; Name Type Nullable Default Comments ------- ------------ -------- ------- -------- COUNTRY VARCHAR2(20) Y CITY VARCHAR2(20) Y SQL> select * from test; COUNTRY CITY ---
假如有如下表,其中各个i值对应的行数是不定的 SQL> select * from t; I A D ---------- ---------- ------------------- 1 b 2008-03-27 10:55:42 1 a 2008-03-27 10:55:46 1 d 2008-03-27 10:55:30 2 z 2008-03-27 10:55:55 2 t 200
sys_connect_by_path select i,ltrim(max(sys_connect_by_path(a,',')),',') afrom(select i,a,d,min(d) over(partition by i) d_min,(row_number() over(order by i,d))+(dense_rank() over (order by i)) numidfrom t)start with d=d_min connect by numid-1=prior nu
Firebird 同一字段的多行合并为一行用LIST函数类似于MYSQL的GROUP_CONCAT. 具体用法如下: SELECT LIST(a.GG_NAME||':'||a.GG_VALUE) as GuiGEName, a.SP_IDFROM SP_GUIGE a group by a.SP_ID
(转载)http://blog.csdn.net/wxwstrue/article/details/6784774 Union all join 是平行合并 为水平连接 Union all 是垂直合并 是将两个结果联结起来 Union all 的语法: [SQL 语句 1] Union all [SQL 语句 2] Union 语法跟Union all 一样 Union 会排除重复记录 效果类似 DISTINCT *----------------------------- 合并数据集合的理论基
using System; using System.Collections.Generic; using System.ComponentModel; using System.Drawing; using System.Drawing.Design; using System.Windows.Forms; /// <summary> /// DataGridView行合并.请对属性MergeColumnNames 赋值既可 /// </summary> public parti