[darkfreak]

Problem: query results get ordered even though I don't want them to get.

Code:

SELECT * FROM person WHERE persID IN (202,173,437);

The above will get the result rows in ascending persID order - 173,202,437. I would like to get the result rows in the same order I've listed them in IN-part: 202,173,437.

Is it possible to tell MySQL to get the rows in my order by changing that query somehow or do I have to use another approach?

I tried the following with no success:

Code:

SELECT *,'' AS dumb FROM person WHERE persID IN (202,173,437) ORDER BY dumb;

[dennispopel]

Hello,

Try ORDER BY persID

[TizMe]

Give this a whirl.

SELECT * FROM person WHERE persID IN (202) UNION SELECT * FROM person WHERE persID IN (173) UNION SELECT * FROM person WHERE persID IN (437);

[NeverMind]

Originally Posted by dennispopel

Hello,

Try ORDER BY persID

the results are being sorted as if he used that.. but he does NOT want that!
he wants the order to be as provided in the IN() ..
I've tried similar query here and it's also sorting it in ascending order.I am not sure why it's behaving like this..


edit: UNION is only for MySQL 4.x and above.. and I guess they would be slow..
also, if you are having one value why use IN() ?

[darkfreak]

Little more explanation:

I have tables 'person' and 'group'. The 'person' -table contains usual personal data (name, address etc.) and the group should be a linker table with only 3 columns: groupID, groupOrderNum and group_persID.

The idea is to collect groups of persons: in each group there can be a number of different persons (identified by groupID and persID) and the table should "remember" the order in which the user added the persons to the group. This cannot be alphabetical order and that's why I have the groupOrderNum -field which tells the person's position in the group.

The problem appears when I am doing a html UI for this database. I have two forms on the same page: one for person list (where user can pick up any person) and another for the group which shows the persons user has added to the group. Altough PHP maintains the correct order of persIDs in a temporary array, when I update the group list - after the user has added a new person in it - with the above query, the listing gets in different order than in which the user actually added the persons.

[darkfreak]

Originally Posted by TizMe

Give this a whirl.
SELECT * FROM person WHERE persID IN (202) UNION SELECT * FROM person WHERE persID IN (173) UNION SELECT * FROM person WHERE persID IN (437);

Thanks. This does the trick, even though it's not very elegant if I have, say, 50-100 persons in the group

As NeverMind pointed out, this could be simplified a bit by not using the IN:

Code:

SELECT * FROM person WHERE persID=202 UNION SELECT * FROM person WHERE persID=173 UNION SELECT * FROM person WHERE persID=437;

Strangely, even the query below will order the result:

Code:

SELECT * FROM person WHERE persID=202 OR persID=173 OR persID=437;

I guess this is some MySQL query-optimization feature...?