html:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<?php header("content-type:text/html;charset=utf-8");?>
<script src="jquery-3.2.1.min.js"></script>
</head>
<body>
<form action="PDO_insert.php" method="post">
Name: <input type="text" name="name" id="name"/>
<input type="submit" value='查询' id="btn"/>
</form>
<script type="text/javascript">
var name=document.getElementById('name').value;
$("#btn").on("click", function () {
$.ajax({
type: "POST",
url: "PDO_insert.php",//url放的是当前页面请求的后台地址。
data:{name:name},
async:false,
dataType: "json",
success: function (data) {
var result=data;
//var result = eval('[' data ']');
alert(result);
},
error: function () {
alert("请求失败！");
}
});
});
</script>
</body>
</html>
<?php
$host = 'localhost';
$database = 'test';
$username = 'root';
$password = 'root';
$selectName = $_POST['name'];
$pdo = new PDO("mysql:host=$host;dbname=$database", $username, $password);//创建一个pdo对象
$pdo->exec("set names 'utf8'");//设置数据库编码
$sql = "select * from user where name = ?";
//$sql = "select * from user";
$stmt = $pdo->prepare($sql);
$rs = $stmt->execute(array($selectName));
if ($rs){
// PDO::FETCH_ASSOC 关联数组形式
// PDO::FETCH_NUM 数字索引数组形式
while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
global $name,$age;
$name = $row['name'];
$age = $row['age'];
}
}
$data='{name:"'.$name.'",age:"'.$age.'"}';
echo json_encode($data); //打印出："{name:\"1\",age:\"1\"}"
?>
为什么每次获取的都是前一次查询的数据？
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
You are equivalent to two queries, the first is a form query, the second is an ajax query, you put <input type="submit" value='query' id="btn"/> this Try putting it outside the form