java - oracle中varchar的OrderBy

Question

下面是我的一个表(MyTABLE)的列数据(ORDER)，

a
a.1
a.1.1
a.2.0
a.1.10
a.1.4
a.20.1
a.2.2.1
a.4.3.1
a.4
a.40

我想按以下方式订购，

a
a.1
a.1.1
a.1.4
a.2.0
a.2.2.1
a.4
a.4.3.1
a.20.1
a.40
b.*....(if any data present which has b prefixed etc.,)

我想知道这是否可以在获取结果时在数据库级别本身实现？如果没有，那么我们将如何在 Java 中完成它？

Answer 1

SQL Fiddle

Oracle 11g R2 架构设置:

CREATE TABLE MyTable ( name ) AS
          SELECT 'a' FROM DUAL
UNION ALL SELECT 'a.1.4' FROM DUAL
UNION ALL SELECT 'a.2.2.1' FROM DUAL
UNION ALL SELECT 'a.1.1' FROM DUAL
UNION ALL SELECT 'a.1' FROM DUAL
UNION ALL SELECT 'a.40' FROM DUAL
UNION ALL SELECT 'a.4' FROM DUAL
UNION ALL SELECT 'a.4.3.1' FROM DUAL
UNION ALL SELECT 'a.20.1' FROM DUAL
UNION ALL SELECT 'b.1' FROM DUAL
UNION ALL SELECT 'a.2.0' FROM DUAL

查询 1:

SELECT *
FROM   MyTable
ORDER BY
       REGEXP_SUBSTR( name, '[^.]+', 1, 1 ),
       TO_NUMBER( REGEXP_SUBSTR( name, '[^.]+', 1, 2 ) ) NULLS FIRST,
       TO_NUMBER( REGEXP_SUBSTR( name, '[^.]+', 1, 3 ) ) NULLS FIRST,
       TO_NUMBER( REGEXP_SUBSTR( name, '[^.]+', 1, 4 ) ) NULLS FIRST

Results :

|    NAME |
|---------|
|       a |
|     a.1 |
|   a.1.1 |
|   a.1.4 |
|   a.2.0 |
| a.2.2.1 |
|     a.4 |
| a.4.3.1 |
|  a.20.1 |
|    a.40 |
|     b.1 |

SQL Fiddle

MySQL 5.6 架构设置:

CREATE TABLE MyTable ( name VARCHAR(20) );

INSERT INTO MyTable
          SELECT 'a' FROM DUAL
UNION ALL SELECT 'a.1.4' FROM DUAL
UNION ALL SELECT 'a.2.2.1' FROM DUAL
UNION ALL SELECT 'a.1.1' FROM DUAL
UNION ALL SELECT 'a.1' FROM DUAL
UNION ALL SELECT 'a.40' FROM DUAL
UNION ALL SELECT 'a.4' FROM DUAL
UNION ALL SELECT 'a.4.3.1' FROM DUAL
UNION ALL SELECT 'a.20.1' FROM DUAL
UNION ALL SELECT 'b.1' FROM DUAL
UNION ALL SELECT 'a.2.0' FROM DUAL;

查询 1:

SELECT name
FROM   MyTable
ORDER BY
       SUBSTRING_INDEX( name, '.', 1 ),
       CASE WHEN SUBSTRING_INDEX( name, '.', 2 ) = SUBSTRING_INDEX( name, '.', 1 ) THEN -1 ELSE CAST( SUBSTRING_INDEX( SUBSTRING_INDEX( name, '.', 2 ), '.', -1 ) AS SIGNED ) END,
       CASE WHEN SUBSTRING_INDEX( name, '.', 3 ) = SUBSTRING_INDEX( name, '.', 2 ) THEN -1 ELSE CAST( SUBSTRING_INDEX( SUBSTRING_INDEX( name, '.', 3 ), '.', -1 ) AS SIGNED ) END,
       CASE WHEN SUBSTRING_INDEX( name, '.', 4 ) = SUBSTRING_INDEX( name, '.', 3 ) THEN -1 ELSE CAST( SUBSTRING_INDEX( SUBSTRING_INDEX( name, '.', 4 ), '.', -1 ) AS SIGNED ) END

Results :

|    name |
|---------|
|       a |
|     a.1 |
|   a.1.1 |
|   a.1.4 |
|   a.2.0 |
| a.2.2.1 |
|     a.4 |
| a.4.3.1 |
|  a.20.1 |
|    a.40 |
|     b.1 |