Question

我对PHP不太好，但我知道其他一些类似的语言。

现在我要做的是获取表中有多少行。这是我的代码。

$result = mysql_query("SELECT COUNT(*) FROM list");
$num_rows = mysql_num_rows($result);
echo $num_rows;

现在这个代码返回1，当实际有3.这是为什么？谢谢你的帮助。

Answer 1

试试这样：

$result = mysql_query("SELECT COUNT(*) FROM list");
$num_rows = mysql_fetch_object($result);
print_r($num_rows);

注意：不推荐使用Mysql_ *函数。因此不推荐。

Answer 2

<?php
$con=mysqli_connect("example.com","peter","abc123","my_db");
// Check connection
if (mysqli_connect_errno())
  {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
  }

$result = mysqli_query($con,"SELECT COUNT(*) as total_row FROM list");

echo "<table border='1'>
<tr>
<th>total_row</th>
</tr>";

while($row = mysqli_fetch_array($result))
  {
  echo "<tr>";
  echo "<td>" . $row['total_row'] . "</td>";
  echo "</tr>";
  }
echo "</table>";

mysqli_close($con);
?>

Answer 3

$result = mysql_query("SELECT COUNT(*) as total FROM list");
$num_rows = mysql_num_rows($result);
echo $num_rows; // output 1;

$rows = mysql_fetch_object($result);
echo $rows->total; // output 3;

Answer 4

你应该这样做：

$result = mysql_query("SELECT * FROM list");
$num_rows = mysql_num_rows($result);
echo $num_rows;

如果您希望获得COUNT的总行数，可以这样做：

$result = mysql_query("select count(*) FROM list");
$row = mysql_fetch_array($result);
echo $row[0];

Answer 5

检查此

$result = mysql_fetch_array(mysql_query("SELECT COUNT(*) as count FROM list"));
echo $result['count'];

Answer 6

它返回单列中的行数，然后只返回1

<强>参见： http://dev.mysql.com/doc/refman/5.1/en/counting-rows.html

Answer 7

仅更改您的查询

$result = mysql_query("SELECT * FROM list");
$num_rows = mysql_num_rows($result);
echo $num_rows;

Answer 8

它返回一行，因为下面的查询只返回一个值，即行数。

$result = mysql_query("SELECT COUNT(*) FROM list");

我认为这应该有所帮助：

$result = mysql_query("SELECT COUNT(*) FROM list");
$num_rows = $result->fetchColumn();
echo $num_rows;

MySQL - 返回表中的行数

8 个答案: