如果我们增加了一个ID给每个表，并依靠插入顺序意味着什么（或者，如果存在一些其他的序号或排序使用），你可以这样做：
更新检查基于与ROW_NUMBER（）的文件夹：
实施例的测试设置：http://rextester.com/VXZIP45848
create table a (
id int not null identity(1,1)
, one varchar(32)
, two varchar(32)
, three varchar(32))
insert into a values
('folder1','detail1','detail10')
,('folder1','detail2','detail20')
,('folder1','detail3','detail30')
,('folder1','detail 98','detail 198')
,('folder2','detail1','detail10')
,('folder2','detail2','detail20')
,('folder2','detail3','detail30')
,('folder1','detail99','detail 199')
,('folder3','detail1','detail10')
,('folder3','detail2','detail20')
,('folder3','detail3','detail30')
,('folder4','detail1','detail10')
,('folder4','detail2','detail20')
,('folder4','detail3','detail30');
create table b (
id int not null identity(1,1)
, one varchar(32)
, two varchar(32)
, three varchar(32))
insert into b values
('folder1','detail3','detail30')
,('folder1','detail2','detail20')
,('folder1','detail1','detail10')
,('folder2','detail1','detail10')
,('folder2','detail2','detail20')
,('folder2','detail3','detail30')
,('folder3','detail1','detail10')
,('folder3','detail3','detail30')
,('folder3','detail2','detail20')
,('folder4','detail1','detail10')
,('folder4','detail3','detail30')
,('folder5','detail5','detail50');
/* show all a and all b when matched and when not */
select a.*, b.*, diff=case
when a.rn=b.rn then ''
when a.id is null then 'not in a'
when b.id is null then 'not in b'
when a.rn!=b.rn then 'switched'
else '?'
end
from (select * ,rn = row_number() over (partition by one order by id)
from a) as a
full outer join
(select * ,rn = row_number() over (partition by one order by id)
from b) as b
on a.one=b.one
and a.two=b.two
and a.three=b.three
结果：
+------+---------+-----------+------------+------+------+---------+---------+----------+------+----------+
| id | one | two | three | rn | id | one | two | three | rn | diff |
+------+---------+-----------+------------+------+------+---------+---------+----------+------+----------+
| 1 | folder1 | detail1 | detail10 | 1 | 3 | folder1 | detail1 | detail10 | 3 | switched |
| 2 | folder1 | detail2 | detail20 | 2 | 2 | folder1 | detail2 | detail20 | 2 | |
| 3 | folder1 | detail3 | detail30 | 3 | 1 | folder1 | detail3 | detail30 | 1 | switched |
| 4 | folder1 | detail 98 | detail 198 | 4 | NULL | NULL | NULL | NULL | NULL | not in b |
| 8 | folder1 | detail99 | detail 199 | 5 | NULL | NULL | NULL | NULL | NULL | not in b |
| 5 | folder2 | detail1 | detail10 | 1 | 4 | folder2 | detail1 | detail10 | 1 | |
| 6 | folder2 | detail2 | detail20 | 2 | 5 | folder2 | detail2 | detail20 | 2 | |
| 7 | folder2 | detail3 | detail30 | 3 | 6 | folder2 | detail3 | detail30 | 3 | |
| 9 | folder3 | detail1 | detail10 | 1 | 7 | folder3 | detail1 | detail10 | 1 | |
| 10 | folder3 | detail2 | detail20 | 2 | 9 | folder3 | detail2 | detail20 | 3 | switched |
| 11 | folder3 | detail3 | detail30 | 3 | 8 | folder3 | detail3 | detail30 | 2 | switched |
| 12 | folder4 | detail1 | detail10 | 1 | 10 | folder4 | detail1 | detail10 | 1 | |
| 13 | folder4 | detail2 | detail20 | 2 | NULL | NULL | NULL | NULL | NULL | not in b |
| 14 | folder4 | detail3 | detail30 | 3 | 11 | folder4 | detail3 | detail30 | 2 | switched |
| NULL | NULL | NULL | NULL | NULL | 12 | folder5 | detail5 | detail50 | 1 | not in a |
+------+---------+-----------+------------+------+------+---------+---------+----------+------+----------+
由于没有序号或排序，找到的“开关”的情况下是不可能在这种情况下。
实施例的测试设置：http://rextester.com/YEIAN6814
/* since there is no ordinal or sort,
finding cases of 'switching' aren't possible in this case. */
create table a (one varchar(32), two varchar(32), three varchar(32))
insert into a values
('folder1','detail1','detail10')
,('folder1','detail2','detail20')
,('folder1','detail3','detail30')
,('folder2','detail1','detail10')
,('folder2','detail2','detail20')
,('folder2','detail3','detail30')
,('folder3','detail1','detail10')
,('folder3','detail2','detail20')
,('folder3','detail3','detail30')
,('folder4','detail1','detail10')
,('folder4','detail2','detail20')
,('folder4','detail3','detail30');
create table b (one varchar(32), two varchar(32), three varchar(32))
insert into b values
('folder1','detail3','detail30')
,('folder1','detail2','detail20')
,('folder1','detail1','detail10')
,('folder2','detail1','detail10')
,('folder2','detail2','detail20')
,('folder2','detail3','detail30')
,('folder3','detail1','detail10')
,('folder3','detail3','detail30')
,('folder3','detail2','detail20')
,('folder4','detail1','detail10')
,('folder4','detail3','detail30')
,('folder5','detail5','detail50'); /* added this value for example*/
全外连接：显示所有a和所有b要么匹配或不
/* show all a and all b when matched and when not */
select a.*, b.*
, diff=case
when a.one is null then 'not in a'
when b.one is null then 'not in b'
else ''
end
from a
full outer join b on a.one =b.one
and isnull(a.two,'') =isnull(b.two,'')
and isnull(a.three,'')=isnull(b.three,'')
--and (a.two =b.two or (a.two is null and b.two is null))
--and (a.three=b.three or (a.three is null and b.three is null))
+---------+---------+----------+---------+---------+----------+----------+
| one | two | three | one | two | three | diff |
+---------+---------+----------+---------+---------+----------+----------+
| folder1 | detail1 | detail10 | folder1 | detail1 | detail10 | |
| folder1 | detail2 | detail20 | folder1 | detail2 | detail20 | |
| folder1 | detail3 | detail30 | folder1 | detail3 | detail30 | |
| folder2 | detail1 | detail10 | folder2 | detail1 | detail10 | |
| folder2 | detail2 | detail20 | folder2 | detail2 | detail20 | |
| folder2 | detail3 | detail30 | folder2 | detail3 | detail30 | |
| folder3 | detail1 | detail10 | folder3 | detail1 | detail10 | |
| folder3 | detail2 | detail20 | folder3 | detail2 | detail20 | |
| folder3 | detail3 | detail30 | folder3 | detail3 | detail30 | |
| folder4 | detail1 | detail10 | folder4 | detail1 | detail10 | |
| folder4 | detail2 | detail20 | NULL | NULL | NULL | not in b |
| folder4 | detail3 | detail30 | folder4 | detail3 | detail30 | |
| NULL | NULL | NULL | folder5 | detail5 | detail50 | not in a |
+---------+---------+----------+---------+---------+----------+----------+
左联接时：所有a， b匹配时
/* show all a, b matches */
select a.*, b.*
from a
left join b on a.one =b.one
and isnull(a.two,'') =isnull(b.two,'')
and isnull(a.three,'')=isnull(b.three,'')
--and (a.two =b.two or (a.two is null and b.two is null))
--and (a.three=b.three or (a.three is null and b.three is null))
+---------+---------+----------+---------+---------+----------+
| one | two | three | one | two | three |
+---------+---------+----------+---------+---------+----------+
| folder1 | detail1 | detail10 | folder1 | detail1 | detail10 |
| folder1 | detail2 | detail20 | folder1 | detail2 | detail20 |
| folder1 | detail3 | detail30 | folder1 | detail3 | detail30 |
| folder2 | detail1 | detail10 | folder2 | detail1 | detail10 |
| folder2 | detail2 | detail20 | folder2 | detail2 | detail20 |
| folder2 | detail3 | detail30 | folder2 | detail3 | detail30 |
| folder3 | detail1 | detail10 | folder3 | detail1 | detail10 |
| folder3 | detail2 | detail20 | folder3 | detail2 | detail20 |
| folder3 | detail3 | detail30 | folder3 | detail3 | detail30 |
| folder4 | detail1 | detail10 | folder4 | detail1 | detail10 |
| folder4 | detail2 | detail20 | NULL | NULL | NULL |
| folder4 | detail3 | detail30 | folder4 | detail3 | detail30 |
+---------+---------+----------+---------+---------+----------+
NOT EXISTS（）：所有行a不在b
/* all in a that aren't in b */
select src='a not in b', *
from a
where not exists (
select 1
from b
where a.one=b.one
and isnull(a.two,'') =isnull(b.two,'')
and isnull(a.three,'')=isnull(b.three,'')
);
+------------+---------+---------+----------+
| src | one | two | three |
+------------+---------+---------+----------+
| a not in b | folder4 | detail2 | detail20 |
+------------+---------+---------+----------+
NOT EXISTS（）：从b不在a所有行
/* all in b that aren't in a */
select src='b not in a', *
from b
where not exists (
select 1
from a
where a.one=b.one
and isnull(a.two,'') =isnull(b.two,'')
and isnull(a.three,'')=isnull(b.three,'')
);
+------------+---------+---------+----------+
| src | one | two | three |
+------------+---------+---------+----------+
| b not in a | folder5 | detail5 | detail50 |
+------------+---------+---------+----------+
除外：在a不在b
/* distinct values in a that aren't in b */
select * from a
except
select * from b;
+---------+---------+----------+
| one | two | three |
+---------+---------+----------+
| folder4 | detail2 | detail20 |
+---------+---------+----------+
相交不同的值：不同的值是在a这也是b
/* distinct values that are in a that are also in b */
select * from a
intersect
select * from b;
+---------+---------+----------+
| one | two | three |
+---------+---------+----------+
| folder1 | detail1 | detail10 |
| folder1 | detail2 | detail20 |
| folder1 | detail3 | detail30 |
| folder2 | detail1 | detail10 |
| folder2 | detail2 | detail20 |
| folder2 | detail3 | detail30 |
| folder3 | detail1 | detail10 |
| folder3 | detail2 | detail20 |
| folder3 | detail3 | detail30 |
| folder4 | detail1 | detail10 |
| folder4 | detail3 | detail30 |
+---------+---------+----------+
怎能算法/查询决定table2中的一行是否已被切换或丢失？例如，为什么结果的最后一行没有标记为缺失，而之前的行标记为已切换？ –
有很多方法可以做到这一点。一种方法是使用tablediff工具。 [tablediff utility-msdn]（https://msdn.microsoft.com/zh-cn/library/ms162843.aspx） [tablediff utility intro]（https://www.simple-talk.com/sql/sql） -tools/sql-server-tablediff-utility /） – SqlZim
@StephanLechner，很好的问题。说实话，如果用户可以看到该行已被切换或丢失，它确实很重要。只要整个层次结构在出现差异时显示 –