Question

我有这样的数据：

CODE_VD

N_10_19_xxx
N_0_3_xxx
N_121_131_xxx
N_100_120_xxx
N_80_90_xxx
N_20_29_xxx

你可以看到我需要在N_之后只排序第一个数字，我不知道如何得到这个数字。

我尝试过使用susbsting（CODE_VD，2,3）但不完全符合我的预期。

我想得到这个：

CODE_VD

N_0_3_xxx
N_10_19_xxx
N_20_29_xxx
N_80_90_xxx
N_100_120_xxx
N_121_131_xxx

我该怎么做？

Answer 1

SELECT SUBSTRING(CODE_VD,3, CHARINDEX('_',CODE_VD, 3)-3)

Answer 2

DECLARE @MyTable TABLE
(
    CODE_VD VARCHAR(20)
)

INSERT INTO @MyTable
( CODE_VD )
VALUES
('N_10_19_xxx'),
('N_0_3_xxx'),
('N_121_131_xxx'),
('N_100_120_xxx'),
('N_80_90_xxx'),
('N_20_29_xxx');

SELECT * FROM
(
    SELECT 
        *,
        CONVERT(INT,
        SUBSTRING(mt.CODE_VD, 
            3, 
            CHARINDEX('_', mt.CODE_VD, 3) - 3)) ConvCol
    FROM @MyTable mt
) mt
ORDER BY mt.ConvCol

我转换为int以使排序正常工作，因为100＆gt; 20

Answer 3

declare  @t Table (CODE_VD VARCHAR(MAX))
INSERT INTO @t (CODE_VD)VALUES ('N_10_19_xxx')
INSERT INTO @t (CODE_VD)VALUES ('N_0_3_xxx')
INSERT INTO @t (CODE_VD)VALUES ('N_121_131_xxx')
INSERT INTO @t (CODE_VD)VALUES ('N_100_120_xxx')


;WITH
  sorted
AS
(
  SELECT
    *,
    ROW_NUMBER() OVER (PARTITION BY SUBSTRING(CODE_VD,3, CHARINDEX('_',CODE_VD, 3)-3) ORDER BY CODE_VD) AS sequence_id
  FROM
    @t
)
SELECT
  CODE_VD
FROM
  sorted
WHERE
  sequence_id = 1

使用字符串上的子字符串排序SQL

3 个答案: