相当于Oracle CONNECT BY和LEVEL伪列的SQL Server [英] SQL Server equivalent to Oracle CONNECT BY and LEVEL pseudocolumn

问题描述

请帮助将Oracle查询转换为等效的SQL Server:

Please help converting Oracle query to SQL Server equivalent:

SELECT (LEVEL+1-1) AS lvl 
  FROM dual
CONNECT BY LEVEL <= 10
/

输出的数字是1到10:

The output is numbers from 1 to 10:

LVL
----
1
2
3
...
10

我知道SQL Server中有层次结构方法以及诸如GetLevel之类的内置函数.可以用来获得相同的结果吗?

I know there is hierarchy methods in SQL Server and built-ins like GetLevel and more. Can this be used to get the same results?

根据需要创建双重表(不确定)-从此处复制:

To create dual table if needed (not sure) - copied from here:http://blog.sqlauthority.com/2010/07/20/sql-server-select-from-dual-dual-equivalent/

CREATE TABLE DUAL
(
DUMMY VARCHAR(1)
)
GO
INSERT INTO DUAL (DUMMY)
VALUES ('X')
GO

专门寻找可以使用smth的示例.就像查询中的LEVEL.例如:表格中只有一个开始日期-4/22/2013.但是使用LEVEL，我可以按如下所示进行递增:

Specifically looking for examples that would let use smth. like LEVEL in queries. For example: there is only one start date in the table - 4/22/2013. But with LEVEL I'm able to increment it as follows:

SELECT start_date, start_date+LEVEL-1 AS start_date_btwn
  FROM my_tab
 WHERE id = 1
CONNECT BY LEVEL<=10
/

START_DATE    START_DATE_BTWN
------------------------------
4/22/2013    4/22/2013
4/22/2013    4/23/2013
4/22/2013    4/24/2013
4/22/2013    4/25/2013
......
4/22/2013    4/30/2013

非常感谢大家.

推荐答案

我过去做过的一种方法是像这样查询spt_values:

One way I've done it in the past is querying spt_values like this:

SELECT number
FROM master..spt_values
WHERE 
    type = 'P'
    AND number <= 255

但是，它没有完整的数字列表.另一种选择是创建像这样的递归CTE:

However, it doesn't have a full list of numbers. An alternative option would be to create a Recursive CTE like such:

WITH CTE AS (
  SELECT 1 as Number
  UNION ALL
  SELECT Number+1
  FROM CTE 
  WHERE Number < 100 
)
SELECT * FROM CTE

SQL小提琴演示

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