Question

我目前在MyISAM表中有一个有符号整数集，

查询如下：

SELECT * from some_view ORDER BY value DESC, dateAdded DESC

我收到了这个订单：

零值不被视为+/-但我需要它们大于负值!!!

这是我的实际查询：

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

我有以下内容：

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只有一个无索引列，其中包含-1或1，具体取决于用户投票。这是一个有符号整数。

我选择答案时的视图选择tbl_solution_answers和总和（tbl_solution_answer_votes.vote）

这一切都有效，除了有符号整数的排序。

编辑：投票表中的值仅在用户投票的情况下才存在，否则根本不存在。我想我需要这样的东西：

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

您在两个字段上订购，值和日期添加，尝试取出您添加的日期。

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;

我插入了一些随机值，结果如下：

# 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)

按顺序注意，0＆gt; -1

Answer 2

你应该试试

ORDER BY CAST(value AS SIGNED) DESC

如果您的视图搞砸了类型

MySQL在整数零问题上签署了Order By

2 个答案: