表列出每個記錄的其他表

Question

我想創建一個表上特定列的基礎上與所有其他記錄列出每個記錄的對比表中的對比：

例子：

id | web  | author | book  | isbn | pub 
---------------------------------------------------------------- 
1 | www.a.com | sam | sams book | 12345 | sams pub 
2 | www.b.com | ram | rams book | 54321 | rams pub 
3 | www.c.com | sam | rams book | 67891 | tams pub 
4 | www.b.com | ram | gams book | 65644 | gams pub 
5 | www.a.com | sam | sams book | 11111 | xyzs pub 
6 | www.c.com | tam | tams book | 22222 | abcs pub 
7 | www.c.com | tam | tams book | 33333 | pqrs pub 

所以我想創建一個表上欄網，作者每隔記錄 每個記錄，本書的對比結果

結果表應該是：（結果體重是除了網絡+作者+書重量）

sorceRow|destRow| web | author | book | result weight 
-------------------------------------------------------- 
1  | 2 | 0 | 0  | 0 |  0 
1  | 3 | 0 | 1  | 0 |  1 
1  | 4 | 0 | 0  | 0 |  0 
1  | 5 | 1 | 1  | 1 |  3 
1  | 6 | 0 | 0  | 0 |  0 
1  | 7 | 0 | 0  | 0 |  0 
2  | 3 | 0 | 0  | 1 |  1 
2  | 4 | 1 | 1  | 0 |  2 
2  | 5 | 0 | 0  | 0 |  0 
2  | 6 | 0 | 0  | 0 |  0 
... 
6  | 7 | 1 | 1  | 1 |  3 

什麼是在SQL Server腳本以及C＃中獲得此結果的最快方法？

Answer 1

你可以用非等值線和大量的比較來做到這一點。以下是標準的SQL方法：

select t1.id as sourceRow, t2.id as destRow, 
     (case when t1.web = t2.web then 1 else 0 end) as Web, 
     (case when t1.Author = t2.Author then 1 else 0 end) as Author, 
     (case when t1.Book = t2.Book then 1 else 0 end) as Book, 
     (case when t1.ISBN = t2.ISBN then 1 else 0 end) as ISBN, 
     (case when t1.pub = t2.pub then 1 else 0 end) as pub 
from table t1 join 
    table t2 
    on t1.id < t2.id; 

注意，比較會稍微複雜一點，如果列可能包含NULL值，但您的樣本數據沒有任何。

Answer 2

基本上，表格本身的CROSS JOIN將執行乘法運算Cross Join。 至於比較，它取決於您使用的數據庫服務器 - case或iif（）。

select 
    l.id as sourceRow, 
    r.id as destRow, 
    iif (r.web = l.web, 1, 0) as web, 
    iif (r.author = l.author, 1, 0) as author, 
    .... 
from T1 l 
cross join T1 r 
where l.id < r.id