phpMyAdmin正在向数据库添加额外的行

Question

写入和读取MySql数据库的简单PHP代码。从在phpMyAdmin中手动输入的两行数据开始，然后通过PHP代码插入一个新行，当读回数据库内容时，一切都很好（见下文）。

然而，当在phpMyAdmin上检查数据库时，新行已插入三次而不是一次。有什么想法吗？

PHP代码：

<?php
$con = mysqli_connect("localhost","root","password","database");
// Check connection
if (mysqli_connect_errno()) {
  echo "Failed to connect to MySQL: " . mysqli_connect_error() . "<br>";}
else{
  echo "Connected to MySQL okay <br>";}

// Test inserting new row into database
$str = "INSERT INTO sites (src_name, date, content) VALUES ('BBC', '2016-02-24 08:00:00', 'Bad weather in UK')";
$result = $con->query($str);
if ($result === TRUE){
  echo "New record inserted successfully <br>";}
else{
  echo "Error: ". $con->error . "<br>";}

// Test reading from database
$result = $con->query("SELECT * FROM sites");
if (mysqli_num_rows($result) > 0){
  while($row = $result->fetch_assoc()){
    echo "Source : " . $row["src_name"]. " - Date: " . $row["date"]. " - Content: " . $row["content"]. "<br>";}
  }
mysqli_close($con);
?>

PHP页面输出 - 一切看起来都不错：

phpMyAdmin页面 - 显示3行：