Convert partially non-numeric text into number in MySQL query

Question

Is it possible to convert text into a number within MySQL query? I have a column with an identifier that consists a name and a number in the format of "name-number". The column has VARCHAR type. I want to sort the rows according to the number (rows with the same name) but the column is sorted according to do character order, i.e.

name-1
name-11
name-12
name-2

If I cut off the number, can I convert the 'varchar' number into the 'real' number and use it to sort the rows? I would like to obtain the following order.

name-1
name-2
name-11
name-12

I cannot represent the number as a separate column.

edited 2011-05-11 9:32

I have found the following solution ... ORDER BY column * 1. If the name will not contain any numbers is it safe to use that solution?

_name_ is exactly **name** or it can be any character? I mean: is it a string four chars long or is a real name? — Marco, May 11 '11 at 07:26
possible duplicate of [mysql natural sorting](http://stackoverflow.com/questions/5947765/mysql-natural-sorting) — Shakti Singh, May 11 '11 at 07:39

Marco · Accepted Answer · 2012-04-05T10:25:22.803

286

This should work:

SELECT field,CONVERT(SUBSTRING_INDEX(field,'-',-1),UNSIGNED INTEGER) AS num
FROM table
ORDER BY num;

edited Apr 05 '12 at 10:25

answered May 11 '11 at 07:28

Marco

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could you add an explanation and a link to the documentation? – Angelo Fuchs Jul 03 '17 at 12:37
My string is like "name-abc12". By adding your code, it only works if the initial characters after "-" not starts with a letter. @Marco Can you tell me a way to ignore the letters without a where condition? – Eduardo Nov 06 '18 at 13:52
1

@Eduardo my query is supposed to get the string after the "-" and convert it into a number (it MUST be a number). In your case I'd go on using a regular expression probably... – Marco Nov 06 '18 at 19:42
@Marco regular expression did it, thank you for the tip. – Eduardo Nov 08 '18 at 12:29
[More info](https://www.w3schools.com/sql/func_mysql_substring_index.asp) on this command – Anchith Acharya Oct 23 '20 at 16:35
@Eduardo Marco is using `SUBSTRING_INDEX` which uses a given separator (`-` in this case) to split the string in "columns" and return the portion of that separation that you ask for (with the third argument). All details in the documentation: https://dev.mysql.com/doc/refman/5.7/en/string-functions.html#function_substring-index – perepm Aug 20 '21 at 07:56

mu is too short · Answer 2 · 2011-05-11T07:51:51.427

37

You can use SUBSTRING and CONVERT:

SELECT stuff
FROM table
WHERE conditions
ORDER BY CONVERT(SUBSTRING(name_column, 6), SIGNED INTEGER);

Where name_column is the column with the "name-" values. The SUBSTRING removes everything up before the sixth character (i.e. the "name-" prefix) and then the CONVERT converts the left over to a real integer.

UPDATE: Given the changing circumstances in the comments (i.e. the prefix can be anything), you'll have to throw a LOCATE in the mix:

ORDER BY CONVERT(SUBSTRING(name_column, LOCATE('-', name_column) + 1), SIGNED INTEGER);

This of course assumes that the non-numeric prefix doesn't have any hyphens in it but the relevant comment says that:

name can be any sequence of letters

so that should be a safe assumption.

edited May 11 '11 at 07:51

answered May 11 '11 at 07:27

mu is too short

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Answering my comment, he told us _name_ can be any sequence of chars, so I'm not sure you can use `SUBSTRING(name_column, 6)`. I know, you posted it when he didn't tell us this... – Marco May 11 '11 at 07:36
@Marco: Thanks for the heads up, I added an update that should take care of the new information about the prefixes. But yeah, your SUBSTRING_INDEX is nicer. – mu is too short May 11 '11 at 07:52

score 29 · Answer 3 · answered Nov 16 '16 at 05:23

29

Simply use CAST,

CAST(column_name AS UNSIGNED)

The type for the cast result can be one of the following values:

BINARY[(N)]
CHAR[(N)]
DATE
DATETIME
DECIMAL[(M[,D])]
SIGNED [INTEGER]
TIME
UNSIGNED [INTEGER]

answered Nov 16 '16 at 05:23

Sibin John Mattappallil

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score 17 · Answer 4 · answered May 11 '11 at 07:25

17

You can use CAST() to convert from string to int. e.g. SELECT CAST('123' AS INTEGER);

answered May 11 '11 at 07:25

verdesmarald

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Is that version specific? I need to use `SELECT CAST('123' AS SIGNED INTEGER);` or `SELECT CAST('123' AS UNSIGNED INTEGER);` to get it to work. – Hobo Apr 25 '13 at 14:30

Gaurav · Answer 5 · 2011-05-11T07:38:04.607

10

SELECT *, CAST(SUBSTRING_INDEX(field, '-', -1) AS UNSIGNED) as num FROM tableName ORDER BY num;

edited May 11 '11 at 07:38

answered May 11 '11 at 07:29

Gaurav

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Are you sure that the ORDER BY uses num as a number without using CONVERT? I'm not sure, but it can be.. I'm just asking myself :) – Marco May 11 '11 at 07:35

V R K RAO · Answer 6 · 2016-07-04T10:43:12.233

9

one simple way SELECT '123'+ 0

edited Jul 04 '16 at 10:43

answered Jul 04 '16 at 06:45

V R K RAO

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Although this code may be help to solve the problem, providing additional context regarding _why_ and/or _how_ it answers the question would significantly improve its long-term value. Please [edit] your answer to add some explanation. – Toby Speight Jul 04 '16 at 09:57
This did not answer the question but it was the answer i was looking for. – Sagar Shah Jul 27 '16 at 10:57
your solution is the most elegant and practical - unfortunately you didnt provide it in the context of the question with specific expression for given example - please modify it to be specific. – chukko Mar 03 '17 at 13:44

score 5 · Answer 7 · answered Jan 11 '20 at 10:43

5

cast(REGEXP_REPLACE(NameNumber, '[^0-9]', '') as UNSIGNED)

answered Jan 11 '20 at 10:43

Jayram Kumar

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Exactly what I want :) – prashant May 06 '21 at 08:16
1

It's my fortune, I came out helpful for you. – Jayram Kumar May 07 '21 at 00:02

score 3 · Answer 8 · answered May 11 '11 at 07:26

3

To get number try with SUBSTRING_INDEX(field, '-', 1) then convert.

answered May 11 '11 at 07:26

2

You need to change 1 to -1. http://dev.mysql.com/doc/refman/5.0/en/string-functions.html#function_substring-index – Gaurav May 11 '11 at 07:32

score 2 · Answer 9 · answered Jul 15 '13 at 11:25

if your primary key is a string in a format like

ABC/EFG/EE/13/123(sequence number)
this sort of string can be easily used for sorting with the delimiter("/")

we can use the following query to order a table with this type of key

SELECT * FROM `TABLE_NAME` ORDER BY 
CONVERT(REVERSE(SUBSTRING(REVERSE(`key_column_name`), 1, LOCATE('/', REVERSE(`key_column_name`)) - 1)) , UNSIGNED INTEGER) DESC

score 0 · Answer 10 · edited Jul 10 '21 at 00:03

0

I found it easier to use regex_replace function to strip off all non numeric values from the field and then sort.

SELECT field , CONVERT(REGEXP_REPLACE(field,'[^0-9]',''),UNSIGNED) AS num FROM your_table ORDER BY num;

edited Jul 10 '21 at 00:03

Obsidian

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answered Jul 09 '21 at 14:23

dmishra

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score -2 · Answer 11 · answered Mar 09 '21 at 03:19

-2

select
    `a`.uuid,
    concat('1',REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(`a`.uuid,'-',''),'b','11'),'c','12'),'d','13'),'e','14'),'f','15'),'a','10')),

answered Mar 09 '21 at 03:19

Gank

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Please add some explanation to your answer such that others can learn from it – Nico Haase Mar 09 '21 at 15:16
This one may just be responding to the title of this post - converting text to number (in this case a text uuid string) -- using replace (or pretty much anything else) is generally faster than a regex. This also suggests the idea of using a uuid string as primary key. A plain old autoincrement or perhaps a binary uuid would be faster than conversion to string if that is the goal in this case. – Jeff Clayton Aug 31 '21 at 12:38

score -5 · Answer 12 · answered Apr 13 '17 at 14:46

-5

A generic way to do :

SELECT * FROM your_table ORDER BY LENTH(your_column) ASC, your_column ASC

answered Apr 13 '17 at 14:46

Azzu

1

Convert partially non-numeric text into number in MySQL query

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