Question

我有一个像这样的大型mysql查询：

SELECT u.userid AS `User`
  , SUM(CASE WHEN activitydate='2011-07-01' THEN round(time/60) ELSE 0 END) AS `2011-07-01`
  , SUM(CASE WHEN activitydate='2011-07-02' THEN round(time/60) ELSE 0 END) AS `2011-07-02`
.......
  , SUM(CASE WHEN activitydate='2011-07-30' THEN round(time/60) ELSE 0 END) AS `2011-07-30`
FROM hoursbase h
  JOIN person u
    ON h.userid = u.id
WHERE h.activitydate BETWEEN '2011-07-01' AND '2011-07-30'
GROUP BY h.userid
ORDER BY h.userid

有什么方法可以使用php在循环中放置查询。

此外，我尝试添加一个下拉菜单，在选择时，相应的月份将在查询中更新。

的问候，
Chandru。

Answer 1

如果您不介意查询具有不同的输出格式，您可以像这样重写它：

SELECT u.userid AS `User`
   ,activitydate
   ,sum(round(ifnull(time,0)/60)) as timetaken
FROM hoursbase h
JOIN person u ON h.userid = u.id 
WHERE h.activitydate BETWEEN :startdate AND :enddate  /*note the : params*/ 
GROUP BY h.userid, h.activitydate 
ORDER BY h.userid, h.activitydate

这将首先返回按userid分组的数据，然后按activitydate分组它还会更快地运行批次最后，在php中获取每个用户每个日期的结果会更容易当你改变月份时，你不必改变列数。

以下是如何使用循环在php中循环它：
我已经复制了这个答案中的代码：How do I loop through a MySQL query via PDO in PHP?

// $attrs is optional, this demonstrates using persistent connections, 
// the equivalent of mysql_pconnect 
$attrs = array(PDO::ATTR_PERSISTENT => true);  

// connect to PDO 
$pdo = new PDO("mysql:host=localhost;dbname=test", "user", "password", $attrs);
// the following tells PDO we want it to throw Exceptions for every error. 
// this is far more useful than the default mode of throwing php errors 
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);  
// prepare the statement. the place holders allow PDO to handle substituting 
// the values, which also prevents SQL injection 
$stmt = $pdo->prepare("SELECT u.userid AS `User`.....  ");  
// bind the parameters 
$stmt->bindValue(":startdate", "2011-07-01"); 
$stmt->bindValue(":enddate", "2011-07-31");  
// initialise an array for the results  
$products = array(); 
if ($stmt->execute()) {   
  while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {      
    //do more useful stuff here
    //escape all fields that can be entered by users using htmlspecialchars
    //to prevent XSS exploits.
    echo htmlspecialchars($row['User']);
    echo htmlspecialchars($row['activitydate']);
    echo $row['timetaken'];
  } 
}  
// set PDO to null in order to close the connection 
$pdo = null;

关于htmlspecialchars()
您需要转义用户可以输入并输出到屏幕的所有字符串字段在这种情况下，我转发userid和activitydate，因为我只有95％确定这些是整数和日期字段，如果我100％肯定，我会跳过逃避，但如果我不是我必须逃脱。

<强>链接：
How to escape output in PHP
How do I loop through a MySQL query via PDO in PHP?

mysql查询中的php循环

1 个答案: