PHP - PDO，如何返回select语句中的行数

Question

我有一个简单的声明，但似乎无法从select语句中获取行数，当它非常简单时真的很烦我。我一直在变空。

这是代码

include "connect.php";

$userID = $_POST['userID'];
$threadID = $_POST['threadID'];

$sql1 = "select * from AT_AddThread where AT_ID = :threadID";
$stmt = $conn->prepare($sql1);
$stmt->execute(array(':threadID' => $threadID));
$result = $stmt->fetchColumn(7);
//echo $result;

$sql2 = "select * from TJ_ThreadJoined where TJ_T_ID = :threadID"
$q2 = $conn->prepare($sql2);
$q2->execute(array(':threadID' => $threadID));
$q2->execute();
$rows = $q2->fetchColumn();
echo $rows; //THIS IS where i want to return the number of rows from the select statement

Answer 1

除了fetchColumn，您还可以尝试以下方式：

1. 计算行数

   $rows = $stmt->fetchAll(); echo "count = " . count($rows);

2. 使用rowCount()

   echo "count = " . $stmt->rowCount();

3. 将其添加到查询中：

   SELECT COUNT(*) as rowCount ...

   echo $row['rowCount'];

Answer 2

试试这个：

Telephone

或

echo $q2->rowCount();

$row = $q2->fetch(PDO::FETCH_NUM); echo $row[0]; doc

Answer 3

您始终可以获取上次查询中返回的行数。只需在SQL_CALC_FOUND_ROWS声明

之后添加SELECT即可

$sql2 = "select SQL_CALC_FOUND_ROWS * from TJ_ThreadJoined where TJ_T_ID = :threadID"

然后执行查询SELECT FOUND_ROWS()，获取行，您将获得上次查询的行数。