Question

I currently have a signed integer set in a MyISAM table,

The query is like:

SELECT * from some_view ORDER BY value DESC, dateAdded DESC

I’m getting this order:

1
2
-1
-2
0
0

The zero values aren’t seen as +/- but I need them to be greater than a negative value!!!

This is my actual query:

SELECT * FROM vw_answer sa left join vw_answer_votes av on av.answerID = sa.id WHERE sa.id = 77 ORDER BY av.vote, dateAdded

I have the following:

tbl_users
tbl_solutions - Indexes tbl_users.id as authorID
tbl_solution_answers - Indexes tbl_solutions.id as solutionID
tbl_solution_answer_votes - Indexes tbl_users.id as voterID and tbl_solution_answers
as answerID

tbl_solution_answer_votes only has one none indexed column which contains -1 or 1 depending on the vote cast by a user. This is a signed integer.

my view when I select answers selects tbl_solution_answers and the sum(tbl_solution_answer_votes.vote)

It all works, except the ordering on signed integer.

Edit: Values in the votes table only exist if a user has voted else it simply doesn’t exist. I need something like this I think:

SELECT * FROM tbl_answers sa right join vw_answer_votes av on av.answerID = sa.id
ORDER BY av.vote > 0 desc, av.vote IS NULL, av.vote < 0 desc,  dateAdded DESC

Answer 1

You are ordering on two fields, value and dateadded, try taking out your date added.

create table order_by_neg_test
    (`id` int(11) unsigned not null auto_increment, 
    `value` int(11) signed not null, 
     primary key (`id`)) engine=myisam default charset=utf8;

I inserted some random values and here are the results:

# No order
mysql> select * from order_by_neg_test;
+----+-------+
| id | value |
+----+-------+
|  1 |    45 |
|  2 |     1 |
|  3 |     0 |
|  4 |    -1 |
|  5 |    17 |
|  6 |    27 |
|  7 |    -1 |
+----+-------+
7 rows in set (0.00 sec)

# With an order
mysql> select * from order_by_neg_test order by value desc;
+----+-------+
| id | value |
+----+-------+
|  1 |    45 |
|  6 |    27 |
|  5 |    17 |
|  2 |     1 |
|  3 |     0 |
|  4 |    -1 |
|  7 |    -1 |
+----+-------+
7 rows in set (0.00 sec)

Notice in the order, 0 > -1.