ORDER/SORT Column mixed number and number prefixed by char

问题

I have a varchar column conteining a code, this code could by only numbers, or number prefixed by a char for example i have a column containing this data :

+------+
| Code |
+------+
|  1   |
|  C1  |
|  2   |
|  3   |
|  C3  |
|  F3  |
|  F1  |
|  F17 |
|  C9  |
|  C10 |
|  C47 |
| C100 |
| C134 |
| A234 |
|C1245 |
|   10 |
|  100 |
+------+

And so on ...

I want to sort this column by this rules :

Only numeric code
Prefixed code with the letter part order alfanumerically and numeric part ordered as a number

I want to achieve a resultset ordered like this :

+------+
| Code |
+------+
|  1   |
|  2   |
|  3   |
| 10   |
| 100  |
| A234 |
|  C1  |
|  C3  |
|  C9  |
|  C10 |
|  C47 |
| C100 |
| C134 |
|C1245 |
|  F1  |
|  F3  |
|  F17 |
+------+

How can i get a resultset ordered with this criteria ? I've tried with a query like this :

SELECT Code FROM Code_List ORDER BY case when Code like '%[a-z]%' then 99999999999999999999999999999999 else convert(decimal, Code) end

But i get a result that order first the number and then the prefixed number but the alpha prefixed number is ordered like char and not in the manner i want it...

The only numeric record should be ordered following the rules of the numeric order and no the character order so if the only numeric record are :

+------+
| Code |
+------+
|  1   |
|  47  |
|  2   |
|  3   |
|  6   |
|  100 |
|  112 |
|  10  |

I want to get :

+------+
| Code |
+------+
|  1   |
|  2   |
|  3   |
|  6   |
|  10  |
|  47  |
|  100 |
|  112 |

The Database is Microsoft SQL Server.

回答1:

Assuming there's no spaces before the values and there can only be 1-char prefix:

ORDER BY
  CASE WHEN LEFT(Code, 1) BETWEEN '0' AND '9' THEN ' ' ELSE LEFT(Code, 1) END,
  CAST(STUFF(Code, 1, CASE WHEN LEFT(Code, 1) BETWEEN '0' AND '9' THEN 0 ELSE 1 END, '') AS int)

Alternatively, the second criterion could be rewritten like this:

  CAST(STUFF(Code, 1, PATINDEX('[^0-9]%', Code), '') AS int)

PATINDEX('[^0-9]%', Code) returns 1 if it finds a non-numeric character at the beginning of Code, and 0 otherwise. As a result, STUFF either removes 1 character, or none, i.e. same as previously.

回答2:

 CASE
    WHEN ISNUMERIC(Col) = 1 THEN '@'
    Else LEFT(Col, 1)
 END
,CASE
    WHEN ISNUMERIC(Col) = 1 THEN Convert(int, Col)
    Else Convert(int, RIGHT(Col, LEN(Col) - 1))
 END

回答3:

you might try

...ORDER by ('A'+Code)

回答4:

SELECT Code FROM Code_List ORDER BY Code, CASE WHEN ISNUMERIC(SUBSTRING(Code,1,1)) = 1 THEN CODE ELSE SUBSTRING(Code,2,LEN(Code)-1) END

Obviously assuming that only the first digit can be alpha

来源：https://stackoverflow.com/questions/5735551/order-sort-column-mixed-number-and-number-prefixed-by-char

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