MySQL ORDER BY'ENUM'类型值

Question

I'm having a table:

ID    TYPE     VALUE
1     phone    12345
2     fax      98753
3     address  etc
...

the TYPE col is defined as ENUM with values: 'phone','fax','address' .

Now my query is:

$q = mysql_query(SELECT * FROM tbl ORDER BY id);
while(row = mysql_fetch_array($q)){
    echo $row['type'] . "--->" . $row['value'];
}

The output is ordered by id, first line is phone , then it's fax and then it's address .

But I want the output be order by:

1- All address 2- All Phone 3- All fax

How I could achieve this?

Thanks for your help :-)

Answer 1

SELECT A.*,  
case ID 
  when 3 then 1 
  when 2 then 3 
  when 1 then 2 
  else 4 end as myorder
FROM tbl A 
ORDER BY myOrder

Alternatively update the enum to list the Number first on the type field such as 01.Address, 02.Phone, 03.Fax .. then your order by type instead of ID. The 2nd approach makes it pretty easy to add up to 99 types without having to change code (just data) if you add another type later using the first approach, you have to edit the SQL...

The first approach uses a case statement to generate a calculated column at run time. This new column contains the correct order by substituting the IDs for the order you want (it doesn't change the IDs, it simply defines them in the order you want) and then orders by this new calculated column.

$q = mysql_query(SELECT A.*,  case ID when 3 then 1 when 2 then 3 when 1 then 2 else 4 end as myorder FROM tbl A ORDER BY myOrder);

The second approach involves changing the data in the enum such that it is preceeded by a number which defines the sort you want. Thus if you change the SQL in your sort to sort by Type instead of ID, it would then work.

$q = mysql_query(SELECT * FROM tbl ORDER BY Type);

Answer 2

Try this query -

SELECT * FROM tbl
ORDER BY
  CASE type
    WHEN 'address' THEN 1
    WHEN 'phone' THEN 2
    WHEN 'fax' THEN 3
    ELSE 4
  END

---

Full example:

CREATE TABLE tbl (
  id int(11) DEFAULT NULL,
  type enum ('phone', 'fax', 'address') DEFAULT NULL,
  value int(11) DEFAULT NULL
);

INSERT INTO test.tbl(id, type, value) VALUES
  (1, 'phone', 11),
  (2, 'fax', 22),
  (3, 'address', 33),
  (4, 'fax', 44),
  (5, 'address', 55);

SELECT * FROM tbl
ORDER BY
  CASE type
    WHEN 'address' THEN 1
    WHEN 'phone' THEN 2
    WHEN 'fax' THEN 3
    ELSE 4
  END;

+------+---------+-------+
| id   | type    | value |
+------+---------+-------+
|    3 | address |    33 |
|    5 | address |    55 |
|    1 | phone   |    11 |
|    2 | fax     |    22 |
|    4 | fax     |    44 |
+------+---------+-------+