mysql计数变成PHP变量 [英] mysql count into PHP variable
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问题描述
假设我们有以下查询:
SELECT DISTINCT COUNT(`users_id')FROM`users_table`
此查询将返回表中的用户数。我需要传递这个值到一个PHP变量。我正在使用这个:
$ sql_result = mysql_query($ the_query_from_above)or die(mysql_error());
if($ sql_result)
{
$ nr_of_users = mysql_fetch_array($ sql_result);
}
else
{
$ nr_of_users = 0;
}
请更正我认为必要的代码。
这是最好的方法。
<$> p $ p>
//更改查询 - 不需要DISTINCT
//并将计数别名为num
$ data = mysql_query(' `)AS num FROM`users_table`')或die(mysql_error());
//一个COUNT查询将总是返回1行
//(除非失败,在这种情况下我们死在上面)
//使用fetch_assoc一个好的关联数组 - 更容易使用
$ row = mysql_fetch_assoc($ data);
//从数组中获取使用次数
//'num'是我们如上所述的列别名
$ numUsers = $ row ['num'];
Let say that we have the following query:
SELECT DISTINCT COUNT(`users_id`) FROM `users_table`;
this query will return the number of the users from a table. I need to pass this value to a PHP variable. I'm using this:
$sql_result = mysql_query($the_query_from_above) or die(mysql_error());
if($sql_result)
{
$nr_of_users = mysql_fetch_array($sql_result);
}
else
{
$nr_of_users = 0;
}
please correct my code where you think is necessary.
Which is the best approach. How do you recommend to do this ?
解决方案
Like this:
// Changed the query - there's no need for DISTINCT
// and aliased the count as "num"
$data = mysql_query('SELECT COUNT(`users_id`) AS num FROM `users_table`') or die(mysql_error());
// A COUNT query will always return 1 row
// (unless it fails, in which case we die above)
// Use fetch_assoc for a nice associative array - much easier to use
$row = mysql_fetch_assoc($data);
// Get the number of uses from the array
// 'num' is what we aliased the column as above
$numUsers = $row['num'];
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