这两天我一直在做这个项目。我不知道这段代码有什么错误以及我应该使用什么方法来使我的代码更好，我的 friend 告诉我应用数组但我不熟悉那种方法我尝试在几天内研究和研究但它不起作用。我需要的是制作一个程序来计算 1、2、3、4 和 5 级并显示例如有多少数据(行)在 1 月、2 月、3 月、4 月、5 月、6 月、7 月、8 月达到了 5 级,sep,oct,nov 和 dec，在这个示例代码中，我只显示过滤级别 5，因为我不想让读者感到困惑。感谢你们 :-(

This is My sample table

Table: sample
+-------------+------------------+-----------+
|    date     |     level        |   id      |
+-------------+------------------+-----------+
| 2012-03-01  |      4           |     1     |
| 2012-02-02  |      1           |     2     |
| 2012-04-03  |      4           |     3     |
| 2012-05-14  |      1           |     4     |
| 2010-01-05  |      5           |     5     |
| 2009-01-05  |      2           |     6     |
| 2008-01-05  |      3           |     7     |
| 2012-02-02  |      1           |     8     |
| 2012-06-03  |      4           |     9     |
| 2012-07-14  |      1           |     10    |
| 2010-01-05  |      5           |     11    |
| 2009-01-05  |      2           |     12    |
| 2012-08-05  |      3           |     13    |
+-------------+------------------+-----------+

This query is selecting all data with a year of 2012 and order by date

$query = mysql_query("select * from table where year(date)='2012' order by date");

This while loop generate all the record that $query prefer. In the loop there was the HOPING condition that filter the records with all 5 LEVEL... when the data(produce by $query) is level 5 the $level5 will increment by 1, then that data will under go to another if statement to determined what month the data(produce by $query) belong, let say the data is 2012-05-14, so the data will go in the if statement if(Date_format($ii['date'],'%m'))==05) and increase the $level5_may by 1 and after that...

while($ii=mysql_fetch_array($query))
{
if($ii['level']==5)
{
 $level5++;
  if(Date_format($ii['date'],'%m'))==1)
  {
  $level5_jan++;
  }elseif(Date_format($ii['date'],'%m'))==02)
  {
  $level5_feb++;
  }elseif(Date_format($ii['date'],'%m'))==03)
  {
  $level5_mar++;
  }elseif(Date_format($ii['date'],'%m'))==04)
  {
  $level5_apr++;
  }elseif(Date_format($ii['date'],'%m'))==05)
  {
  $level5_may++;
  }elseif(Date_format($ii['date'],'%m'))==06)
  {
  $level5_jun++;
  }elseif(Date_format($ii['date'],'%m'))==07)
  {
  $level5_jul++;
  }elseif(Date_format($ii['date'],'%m'))==08)
  {
  $level5_aug++;
  }elseif(Date_format($ii['date'],'%m'))==09)
  {
  $level5_sep++;
  }elseif(Date_format($ii['date'],'%m'))==10)
  {
  $level5_oct++;
  }elseif(Date_format($ii['date'],'%m'))==11)
  {
  $level5_nov++;
  }elseif(Date_format($ii['date'],'%m'))==12)
  {
  $level5_dec++;
  }
}
}

this part of the code will now collect the result of the if statement

echo"
number of 5 stars: $level5  <br>
jan:$level5_jan     <br>
feb:$level5_feb     <br>
mar:$level5_mar     <br>
apr:$level5_apr     <br>
may:$level5_may     <br>
jun:$level5_jun     <br>
jul:$level5_jul     <br>
aug:$level5_aug     <br>
sep:$level5_sep     <br>
oct:$level5_oct     <br>
nov:$level5_nov     <br>
dec:$level5_dec     <br>
";

最佳答案

SQL:

"SELECT level, id, date AS UNIX_TIMESTAMP(date) FROM table WHERE year(date) = '2012' ORDER BY date"

PHP:

while($row = mysql_fetch_assoc($query))
{
    $levels = array(); // This is where the data for the monthly counting goes in
    $currentLevel = $row['level']; // The current level in the loop
    $currentDate = date('n', $row['date']); // The current month without leading zeroes

    if ($currentLevel === 5) // Check if the current level equals 5
    {
        $levels[$currentLevel][$currentDate] += 1;
    }
}

应该做你想做的，但没有经过测试。

注意:当然不推荐使用多个查询(性能不好)

编辑

SELECT field1, field2, field3, date AS UNIX_TIMESTAMP(date) FROM table WHERE year(date) = '2012' ORDER BY date)

或试试这个(不确定这是否正常工作):

SELECT *, date AS UNIX_TIMESTAMP(date) FROM ...

UNIX_TIMESTAP

如果您的字段是 typeof timestamp 或 datetime UNIX_TIMESTAMP(date) 将返回自 1971 年 11 月以来的日期(请参阅:http://en.wikipedia.org/wiki/Unix_time)和此处(请参阅:http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_unix-timestamp)

使用 unix 时间戳可以很容易地处理日期 - 您可以轻松地使用它们进行计算并将格式设置为您喜欢的任何格式。

关于php - 使用php和mysql进行数据过滤，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/12970167/