SQL 字母数字排序问题

Question

我发现我们可以对 table 中的列进行排序，即使它是字母数字。

这里我遇到的唯一问题是，如果列数据只是字符，它会抛出错误。

BEGIN TRAN

USE SomeDatabase
CREATE TABLE dbo.Section
(
       Section varchar(50) NULL
)
INSERT INTO dbo.Section (Section.Section) VALUES ('BB')
INSERT INTO dbo.Section (Section.Section) VALUES ('1 ')
INSERT INTO dbo.Section (Section.Section) VALUES ('AB 1')
INSERT INTO dbo.Section (Section.Section) VALUES ('A21')
INSERT INTO dbo.Section (Section.Section) VALUES ('B2')
INSERT INTO dbo.Section (Section.Section) VALUES ('A11')
INSERT INTO dbo.Section (Section.Section) VALUES ('B20')
INSERT INTO dbo.Section (Section.Section) VALUES ('B21')
INSERT INTO dbo.Section (Section.Section) VALUES ('AB10')
INSERT INTO dbo.Section (Section.Section) VALUES ('A10')
SELECT Section
FROM dbo.Section

SELECT Section
FROM dbo.Section
ORDER BY LEFT(Section,PATINDEX('%[0-9]%',Section)-1), -- alphabetical sort
         CONVERT(INT,SUBSTRING(Section,PATINDEX('%[0-9]%',Section),LEN(Section))) -- numerical sort

DROP Table dbo.Section

ROLLBACK

所以，排序 'BB' 就是问题所在。如果你删除 BB 那么一切正常。

Answer 1

从您的代码来看，一个明显的问题是 PATINDEX 如果没有找到任何东西，它将 return 0。因为您随后将 0 - 1 作为长度，所以 LEFT 函数将抛出错误。

试试这个：

...
ORDER BY LEFT(Section
             ,CASE WHEN PATINDEX('%[0-9]%',Section) >= 2
                   THEN PATINDEX('%[0-9]%',Section) - 1
                   ELSE LEN(Section)
                   END
             ), -- alphabetical sort
     CASE WHEN PATINDEX('%[0-9]%',Section) >= 1
          THEN CONVERT(INT,SUBSTRING(Section,PATINDEX('%[0-9]%',Section),LEN(Section) - PATINDEX('%[0-9]%',Section) - 1))
          END -- numerical sort
...

Answer 2

问题是 Patindex 在两个 order by 子句中都返回 0。我在下面更正了。

declare  @Section TABLE
(
       Section varchar(50) NULL
)
INSERT INTO @Section (Section) VALUES ('BB')
INSERT INTO @Section (Section) VALUES ('1 ')
INSERT INTO @Section (Section) VALUES ('AB 1')
INSERT INTO @Section (Section) VALUES ('A21')
INSERT INTO @Section (Section) VALUES ('B2')
INSERT INTO @Section (Section) VALUES ('A11')
INSERT INTO @Section (Section) VALUES ('B20')
INSERT INTO @Section (Section) VALUES ('B21')
INSERT INTO @Section (Section) VALUES ('AB10')
INSERT INTO @Section (Section) VALUES ('A10')
SELECT Section
FROM @Section

SELECT Section
FROM @Section

ORDER BY Section
--LEFT(Section,PATINDEX('%[0-9]%',Section)-1), -- alphabetical sort
--         CONVERT(INT,SUBSTRING(Section,PATINDEX('%[0-9]%',Section),LEN(Section))) -- numerical sort



SELECT Section  
FROM @Section
ORDER BY LEFT(Section,case when PATINDEX('%[0-9]%',Section) < 1 then 1 else PATINDEX('%[0-9]%',Section) end -1), -- alphabetical sort
         case when PATINDEX('%[0-9]%',Section) < 1 then 0 else CONVERT(INT,SUBSTRING(Section,PATINDEX('%[0-9]%',Section),LEN(Section))) end -- numerical sort


Section
--------------------------------------------------
BB
1 
AB 1
A21
B2
A11
B20
B21
AB10
A10


Section
--------------------------------------------------
BB
1 
A10
A11
A21
AB 1
AB10
B2
B20
B21

Answer 3

您可以像这样使用 stuff() 而不是 substring()：

select section
  , alpha = left(section,patindex('%[0-9]%',section+'0')-1)
  , num   = stuff(section,1,patindex('%[0-9]%',section)-1,'')
from section
order by 
    left(section,patindex('%[0-9]%',section+'0')-1)
  , convert(int,stuff(section,1,patindex('%[0-9]%',section)-1,''))

rextester 演示：http://rextester.com/JOXUEE9700

输出：

+---------+-------+------+
| section | alpha | num  |
+---------+-------+------+
| 1       |       | 1    |
| A10     | A     | 10   |
| A11     | A     | 11   |
| A21     | A     | 21   |
| AB 1    | AB    | 1    |
| AB10    | AB    | 10   |
| B2      | B     | 2    |
| B20     | B     | 20   |
| B21     | B     | 21   |
| BB      | BB    | NULL |
+---------+-------+------+

SQL 字母数字排序问题

SQL Alpha Numeric sorting issue

sql

sql-server

natural-sort

sql-server-2008