MySQL 'Order By' - sorting alphanumeric co

Question

I want to sort the following data items in the order they are presented below (numbers 1-12):

1
2
3
4
5
6
7
8
9
10
11
12

However, my query - using order by xxxxx asc sorts by the first digit above all else:

1
10
11
12
2
3
4
5
6
7
8
9

Any tricks to make it sort more properly?

Further, in the interest of full disclosure, this could be a mix of letters and numbers (although right now it is not), e.g.:

A1
534G
G46A
100B
100A
100JE

etc....

Thanks!

update: people asking for query

select * from table order by name asc

Answer 1

Instead of trying to write some function and slow down the SELECT query, I thought of another way of doing this...

Create an extra field in your database that holds the result from the following Class and when you insert a new row, run the field value that will be naturally sorted through this class and save its result in the extra field. Then instead of sorting by your original field, sort by the extra field.

String nsFieldVal = new NaturalSortString(getFieldValue(), 4).toString()

The above means:
- Create a NaturalSortString for the String returned from getFieldValue()
- Allow up to 4 bytes to store each character or number (4 bytes = ffff = 65535)

| field(32)  |  nsfield(161)                            |   
  a1            300610001

---

String sortString = new NaturalSortString(getString(), 4).toString()

import StringUtils;

/**
 * Creates a string that allows natural sorting in a SQL database
 * eg, 0 1 1a 2 3 3a 10 100 a a1 a1a1 b
 */
public class NaturalSortString {

    private String inStr;
    private int byteSize;
    private StringBuilder out = new StringBuilder();

    /**
     * A byte stores the hex value (0 to f) of a letter or number.
     * Since a letter is two bytes, the minimum byteSize is 2.
     *
     * 2 bytes = 00 - ff  (max number is 255)
     * 3 bytes = 000 - fff (max number is 4095)
     * 4 bytes = 0000 - ffff (max number is 65535)
     *
     * For example:
     * dog123 = 64,6F,67,7B and thus byteSize >= 2.      
     * dog280 = 64,6F,67,118 and thus byteSize >= 3.
     *
     * For example:
     * The String, "There are 1000000 spots on a dalmatian" would require a byteSize that can 
     * store the number '1000000' which in hex is 'f4240' and thus the byteSize must be at least 5
     *
     * The dbColumn size to store the NaturalSortString is calculated as:
     * > originalStringColumnSize x byteSize + 1
     * The extra '1' is a marker for String type - Letter, Number, Symbol
     * Thus, if the originalStringColumn is varchar(32) and the byteSize is 5:
     * > NaturalSortStringColumnSize = 32 x 5 + 1 = varchar(161)
     *
     * The byteSize must be the same for all NaturalSortStrings created in the same table.
     * If you need to change the byteSize (for instance, to accommodate larger numbers), you will
     * need to recalculate the NaturalSortString for each existing row using the new byteSize.
     *
     * @param str        String to create a natural sort string from
     * @param byteSize   Per character storage byte size (minimum 2)
     * @throws Exception See the error description thrown
     */
    public NaturalSortString(String str, int byteSize) throws Exception {
        if (str == null || str.isEmpty()) return;
        this.inStr = str;
        this.byteSize = Math.max(2, byteSize);  // minimum of 2 bytes to hold a character
        setStringType();
        iterateString();
    }

    private void setStringType() {
        char firstchar = inStr.toLowerCase().subSequence(0, 1).charAt(0);
        if (Character.isLetter(firstchar))     // letters third
            out.append(3);
        else if (Character.isDigit(firstchar)) // numbers second
            out.append(2);
        else                                   // non-alphanumeric first
            out.append(1);
    }

    private void iterateString() throws Exception {
        StringBuilder n = new StringBuilder();
        for (char c : inStr.toLowerCase().toCharArray()) { // lowercase for CASE INSENSITIVE sorting
            if (Character.isDigit(c)) {
                // group numbers
                n.append(c);
                continue;
            }
            if (n.length() > 0) {
                addInteger(n.toString());
                n = new StringBuilder();
            }
            addCharacter(c);
        }
        if (n.length() > 0) {
            addInteger(n.toString());
        }
    }

    private void addInteger(String s) throws Exception {
        int i = Integer.parseInt(s);
        if (i >= (Math.pow(16, byteSize)))
            throw new Exception("naturalsort_bytesize_exceeded");
        out.append(StringUtils.padLeft(Integer.toHexString(i), byteSize));
    }

    private void addCharacter(char c) {
        //TODO: Add rest of accented characters
        if (c >= 224 && c <= 229) // set accented a to a
            c = 'a';
        else if (c >= 232 && c <= 235) // set accented e to e
            c = 'e';
        else if (c >= 236 && c <= 239) // set accented i to i
            c = 'i';
        else if (c >= 242 && c <= 246) // set accented o to o
            c = 'o';
        else if (c >= 249 && c <= 252) // set accented u to u
            c = 'u';
        else if (c >= 253 && c <= 255) // set accented y to y
            c = 'y';

        out.append(StringUtils.padLeft(Integer.toHexString(c), byteSize));
    }

    @Override
    public String toString() {
        return out.toString();
    }
}

For completeness, below is the StringUtils.padLeft method:

public static String padLeft(String s, int n) {
    if (n - s.length() == 0) return s;
    return String.format("%0" + (n - s.length()) + "d%s", 0, s);
}

The result should come out like the following

-1
-a
0
1
1.0
1.01
1.1.1
1a
1b
9
10
10a
10ab
11
12
12abcd
100
a
a1a1
a1a2
a-1
a-2
áviacion
b
c1
c2
c12
c100
d
d1.1.1
e

Answer 2

This works for type of data: Data1, Data2, Data3 ......,Data21. Means "Data" String is common in all rows.

For ORDER BY ASC it will sort perfectly, For ORDER BY DESC not suitable.

SELECT * FROM table_name ORDER BY LENGTH(column_name), column_name ASC;

Answer 3

If you need to sort an alpha-numeric column that does not have any standard format whatsoever

SELECT * FROM table ORDER BY (name = '0') DESC, (name+0 > 0) DESC, name+0 ASC, name ASC

You can adapt this solutation to include support for non-alphanumeric characters if desired using additional logic.

Answer 4

I know this post is closed but I think my way could help some people. So there it is :

My dataset is very similar but is a bit more complex. It has numbers, alphanumeric data :

1
2
Chair 
3
0
4
5
-
Table
10
13
19
Windows
99
102
Dog

I would like to have the '-' symbol at first, then the numbers, then the text.

So I go like this :

SELECT name, (name = '-') boolDash, (name = '0') boolZero, (name+0 > 0) boolNum 
FROM table 
ORDER BY boolDash DESC, boolZero DESC, boolNum DESC, (name+0), name

The result should be something :

-
0    
1
2
3
4
5
10
13
99
102
Chair
Dog
Table
Windows

The whole idea is doing some simple check into the SELECT and sorting with the result.

Answer 5

I hate this, but this will work

order by lpad(name, 10, 0)  <-- assuming maximum string length is 10
                            <-- you can adjust to a bigger length if you want to

Answer 6

This should sort alphanumeric field like: 1/ Number only, order by 1,2,3,4,5,6,7,8,9,10,11 etc... 2/ Then field with text like: 1foo, 2bar, aaa11aa, aaa22aa, b5452 etc...

SELECT  MyField
FROM MyTable
order by 
    IF( MyField REGEXP '^-?[0-9]+$' = 0, 
    9999999999 ,  
    CAST(MyField AS DECIMAL) 
    ), MyField

The query check if the data is a number, if not put it to 9999999999 , then order first on this column, then order on data with text

Good luck!