自己的計數器

Question

id | num | text 
1 | a | sdfsdf 
2 | a | sdfsdf 
3 | b | sdfsdf 
4 | c | sdfsdf 
5 | a | sdfsdf 
6 | b | sdfsdf 
7 | a | sdfsdf 
8 | c | sdfsdf 

我做的查詢，其中NUM =一個和排序依據ID DESC和我有：

id | num | text 
7 | a | sdfsdf 
5 | a | sdfsdf 
2 | a | sdfsdf 
1 | a | sdfsdf 

我想添加它自己的計數器：

count | id | num | text 
    4 | 7 | a | sdfsdf 
    3 | 5 | a | sdfsdf 
    2 | 2 | a | sdfsdf 
    1 | 1 | a | sdfsdf 

我使用foreach PHP獲取數據：

foreach ($data as $i => $dat) { 
    echo $dat->id . $dat->num . $dat->text; 
} 

我想出頭：

foreach ($data as $i => $dat) { 
    echo $i . $dat->id . $dat->num . $dat->text; 
} 

但是$ i的相反方向

Answer 1

你可以這樣做：

$count = count($data); 
foreach ($data as $i => $dat) { 
    echo ($count - $i) . $dat->id . $dat->num . $dat->text; 
} 

Answer 2

在PHP：

$i = count($data); 
foreach ($data as $dat) { 
    echo $i . $dat->id . $dat->num . $dat->text; 
    $i--; 
} 

Answer 3

你知道，你可以在你的SQL查詢中解決這個問題。這是一個樣本，其對生產管理平臺數據庫實例（MySQL的）一然：

select @curRow := @curRow + 1 AS row_number, issues.* 
from issues, (SELECT @curRow := 0) r 
where project_id = 7 
and tracker_id = 3 
order by 1 desc