[mysql] Convert text into number in MySQL query

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?

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

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.

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]

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

A generic way to do :

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

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

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

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

one simple way SELECT '123'+ 0