如何对varchar列进行排序? [英] How to sort varchar column ?

问题描述

我有一个像这样的表:

I have a table like this:

col1  col2
 1     1
 2     1a
 3     2
 4     10
 5     a-1
 6     a-2

并且col2的类型是varchar，当我默认执行order by col2时，结果如下:

and the type of col2 is varchar, when I do order by col2 default,the result like this:

col2
1
10
1a
2
a-1
a-2

但我想要这样:

but I want it like this:

col2
1
1a
2
10
a-1
a-2

我不想使用用户定义的函数来执行此操作.

I don''t want to do it using user-defined function.
help me!

推荐答案

您想要的是自然的选择.
我知道的任何数据库都不支持它.

原因是大多数数据库索引使用B树索引，其中B代表二进制.排序使用索引.
因此，自然排序将需要全表扫描，这在许多情况下会严重影响性能.

此处 [

What you want is a natural sort.
It isn''t supported by any db that I''m aware of.

The reason for this is that most indexing of databases uses B-Tree index where B stands for Binary. Sorting uses the index.
So natural sorting would need a full table scan which in many cases would be a serious performance hit.

Here[^] is an article on how to implement natural sorting using C#.

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