Question

$sql = "SELECT count(name) FROM `TABLE` WHERE name='$name' ";
$sth=$conn->prepare($sql);
$totalrows = $sth->fetch(PDO::FETCH_ASSOC);

echo "$totalrows";

这是我使用PHP PDO Prepare语句计算总行数的代码，但$totalrows没有回显，它没有任何价值。这段代码有什么错误？

Answer 1

你需要：

# USE "as count" here so it's easy to reference
$sql = "SELECT count(name) as count FROM `TABLE` WHERE name = :name";
# prepare as you have
$sth = $conn->prepare($sql);
# Bind parameters while executing
$sth->execute(array(':name'=>$name));
# Fetch the associate array
$totalrows = $sth->fetch(PDO::FETCH_ASSOC);
# Echo the count
echo $totalrows['count'];

在准备，装订和执行方面审核Example #2 from the manual。

Answer 2

尝试

$sql = "SELECT count(name) FROM `TABLE` WHERE name=? ";
$stmt=$conn->prepare($sql);
$stmt->execute(array($name));
$result = $stmt->setFetchMode(PDO::FETCH_ASSOC);
$rows = $stmt->fetchAll();

现在$ rows是一个包含结果的数组

echo count($rows);

Answer 3

如果您只对记录总数感兴趣，那么您不应该从数据库中获取所有记录，请尝试list(skip=0, limit=50)子句，然后使用GROUP BY

COUNT()

Answer 4

要获取计数，请将代码修改为：取代

$totalrows = $sth->fetch(PDO::FETCH_ASSOC);

使用

$totalrows = $sth->fetchColumn();

Answer 5

在查询后使用count并使用bind_param，这样就不会直接从用户那里收到输入：

$stmt = $conn->prepare("SELECT 'something' FROM 'somewhere' WHERE 'name' =  :name;

//get the user input thru a method and bind it to :name

private $name;

getName($name){

$this->name = $name;
}

$stmt->bindParam(':name');

 $stmt->execute();

PHP PDO预备红外行计数不起作用

5 个答案: