Question

在PostgrSQL上，我这样做没问题：

CREATE SEQUENCE serial_olw START 1;
update collections_elements set elementorder=(nextval('serial_olw')-1) WHERE collections_elements.collectionid=1;
drop sequence serial_olw;

示例：1,2,3,4,5,6 ......

在MS-SQL Server 2008上没有SEQUENCE函数...所以我尝试了这个：

DECLARE @i int
SET @i = 0

WHILE @i<44
    BEGIN
    UPDATE collections_elements set elementorder=(@i) WHERE collections_elements.collectionid=1
        SET @i=@i+1
    END

但我对那个循环没有成功......

示例：43,43,43,43,43 ......

解决方案的任何想法？

Answer 1

Update t
Set t.elementorder = t.RowID
From
(
    Select ROW_NUMBER() Over(Order by collectionid) as RowID, * From collections_elements
)t

<强> SQL Fiddle

Answer 2

update T
set elementorder = rn
from
  (
    select elementorder,
           row_number() over(order by (select 0)) as rn
    from collections_elements
    where collectionid = 1
  ) T

SE-Data

Answer 3

尝试这样的事情 - 内联变量增量：

DECLARE @i int 
SET @i = 0

WHILE @i<44 
BEGIN
    UPDATE collections_elements 
    SET @i = elementorder = @i + 1 
    WHERE collections_elements.collectionid=1 
END

Answer 4

此脚本是一个示例。尝试这样的事情-内联变量增量：

ThreadPool

SQL-Server 2008：如何使用计数器更新字段？

4 个答案: