【Transact-SQL】通过递归来实现：将多条记录的某个字段的值，用斜杠拼接在一起

 需要把表@tt中的idd相同的记录中tchar字段的内容拼接在一起，结果如下

1,'abc/xyz/ggg'

2,'111/soft'

 

实验代码如下：

declare @tt table(idd int,tchar varchar(10))  insert into @tt     select 1,'abc' union all select 1,'xyz' union all select 1,'ggg' union all select 2,'111' union all select 2,'soft'    ;with c as ( select idd,        tchar, 	   row_number() over(partition by idd order by tchar) as row from @tt  ),  cc   --递归CTE as ( 	select idd,            cast(tchar as varchar(1000)) as ch, 		   row 	from c  	where row = 1      union all  	select cc.idd,            ch=cast(cc.ch+'/'+c.tchar as varchar(1000)),            c.row 	from cc 	inner join c  			on c.idd = cc.idd 			   and c.row = cc.row+1 ), ccc as ( select idd,ch,row,        row_number() over(partition by idd order by row desc) as rownum from cc )  select * from ccc  where rownum=1 /* idd	ch	        row	rownum 1	abc/ggg/xyz	3	1 2	111/soft	2	1 */