根据 Select Order By Results 更新 OrderID？

Question

我用的是SQLite 3，我有一个MyTable表，如下：

    Create table mytable (ID as INTEGER, OrderID as INTEGER, a as INTGER, b as INTEGER);

    Insert into mytable (ID, OrderID,a,b) values (1, 1,1,1);
    Insert into mytable (ID, OrderID,a,b) values (1, 2,1,2);
    Insert into mytable (ID, OrderID,a,b) values (2, 1,1,3);
    Insert into mytable (ID, OrderID,a,b) values (2, 3,2,1);
    Insert into mytable (ID, OrderID,a,b) values (3, 1,2,3);

现在如果我使用以下语句：

Select * from mytable ORDER BY a desc, b desc;

我将以不同的顺序获取所有行，如下所示：

    (3, 1, 2, 3); 
    (2, 3, 2, 1); 
    (2, 1, 1, 3); 
    (1, 2, 1, 2); 
    (1, 1, 1, 1);

现在我想将订单ID更新为上面结果中出现的行的序号，如下：

    (3, 1, 2, 3); 
    (2, 2, 2, 1); 
    (2, 3, 1, 3); 
    (1, 4, 1, 2); 
    (1, 5, 1, 1);

怎么做？

Answer 1

试试这个：-

      Select ROW_NUMBER() OVER (ORDER BY (SELECT 1 ) ) AS ordNo, * INTO #TempTable  from 
         mytable ORDER BY a desc, b desc;

UPDATE mytable SET OrderID = ordNo FROM #TempTable WHERE mytable.ID =#TempTable.ID AND mytable.a=#TempTable.a AND mytable.b=#TempTable.b

Answer 2

假设a 和b 值是唯一的：

update mytable t
    set orderid = (select count(*)
                   from mytable t2
                   where t2.a > t.a or
                         (t2.a = t.a and t2.b >= t.b)
                  );

Answer 3

有一个列 [rowid][1] 负责每个 rowid

典型 SQLite 数据库架构中的大多数表都是 rowid 表。 Rowid 表的区别在于它们都有一个唯一的、非 NULL、有符号的 64 位整数 rowid，用作底层 B 树存储引擎中数据的访问密钥。

由于旧的 SQLite 版本不支持 ROW_NUMBER 窗口函数，您可以使用select 中的子查询来实现。

您可以尝试使用关联子查询和UPDATE by rowid。

架构 (SQLite v3.18)

 Create table mytable (ID  INT, OrderID  INT, a  INT, b  INT);

    Insert into mytable (ID, OrderID,a,b) values (1, 1,1,1);
    Insert into mytable (ID, OrderID,a,b) values (1, 2,1,2);
    Insert into mytable (ID, OrderID,a,b) values (2, 1,1,3);
    Insert into mytable (ID, OrderID,a,b) values (2, 3,2,1);
    Insert into mytable (ID, OrderID,a,b) values (3, 1,2,3);


update mytable 
set orderid= 
(
   SELECT (select count(*) 
              from mytable tt
             where tt.a > t1.a or
                (tt.a = t1.a and tt.b >= t1.b)) rn
    FROM mytable t1
    where mytable.rowid=t1.rowid
);

---

查询 #1

SELECT * FROM mytable order by OrderID;

| ID  | OrderID | a   | b   |
| --- | ------- | --- | --- |
| 3   | 1       | 2   | 3   |
| 2   | 2       | 2   | 1   |
| 2   | 3       | 1   | 3   |
| 1   | 4       | 1   | 2   |
| 1   | 5       | 1   | 1   |

---

View on DB Fiddle