Php 使用prepare语句的CRUD无效。
数据库连接正在工作。类中的SELECT和UPDATE函数根本不起作用。它甚至没有显示错误来帮助我解决问题。我正在尝试学习如何使用prepare、bind param和execute语句。请有人帮我看一下代码，并告诉我可能有什么问题。只是花了很多时间在这上面，根本不知道问题出在哪里。我是一个新手，正在写我的第一个代码。非常感谢Php 使用prepare语句的CRUD无效。,php,database,select,mysqli,Php,Database,Select,Mysqli,数据库连接正在工作。类中的SELECT和UPDATE函数根本不起作用。它甚至没有显示错误来帮助我解决问题。我正在尝试学习如何使用prepare、bind param和execute语句。请有人帮我看一下代码，并告诉我可能有什么问题。只是花了很多时间在这上面，根本不知道问题出在哪里。我是一个新手，正在写我的第一个代码。非常感谢 <?php class connect_dbase{ public $mysqli; public function connectio
<?php class connect_dbase{
public $mysqli;
public function connection($host="localhost",$user="root",$password="london",$db_name="users")
{
$this->mysqli=new mysqli($host,$user,$password,$db_name);
if ($this->mysqli->connect_error) {
die('Connect Error: ' . $this->mysqli->connect_error);
}
else{
echo " Database connection successful";
}
}
public function display_all($id){
if($stmt = $this->mysqli->prepare("SELECT * FROM user WHERE id =?")){
/* bind parameters for markers */
$stmt->bind_param('i',$id);
/* execute query */
$stmt->execute();
if($stmt->num_row() >0){
echo 'Total results: ' . $resultrol->num_rows;
$result = $stmt->get_result();
while ($row = $result->fetch_assoc()) {
echo $row['name'];
echo $row['email'];
echo $row['address'];}
}
else { echo "no result found";}
}
else
{
echo "cant prepare result";
}
}
public function update_post($name, $address,$email,$mob,$id)
{
$up="UPDATE user SET name=?, address =?,email=?,mobile=? WHERE id =?";
if($stmt=$mysqli->prepare($up))
{
$stmt->bind_param("sssii", $name, $address,$email,$mob,$id);
if($stmt->excute()) {
echo " post updated";
header('location:index.php');
}
else
{
echo "post not executed";
}
}else{ echo " cannot prepare statement";}
}
}
$connect_dbase=new connect_dbase();
$connect_dbase->connection();
$connect_dbase->display_all(2);
$connect_dbase-> update_post("john","kkkkk","kkk@yahoo.com",98765,2);
// These 2 functions- $connect_dbase->display_all(2); and
$connect_dbase-> update_post("john","kkkkk","kkk@yahoo.com",98765,2); are not working when called from the class above .
?>
我同意@MikeBrant的评论。如果您想在尝试调用之前确保连接成功，那么应该在构造函数中进行连接 这里还有一个提示：
if($stmt->num_row() >0){
您需要使用将结果集从服务器传输到客户端，然后num_rows（）将起作用。但是，如果结果集非常大，请小心，它可能会占用太多内存。考虑到Mike和Bill的输入，我已修改了您的代码，使其能够正常工作。它可能需要更多的工作，但至少应该给你一个起点。我创建了一个包含三个字段的测试数据库，id、name和email，但是您应该能够插入自己的数据库和字段，并且仍然可以使用
<?php
class connect_dbase {
public $mysqli;
public function connection($host="localhost",$user="root",$password="",$db_name="test")
{
$this->mysqli=new mysqli($host,$user,$password,$db_name);
if ($this->mysqli->connect_error) {
die('Connect Error: ' . $this->mysqli->connect_error);
} else {
// return a true value here if successful, that way you can check
// if your connection was established
return true;
}
}
public function display_all($id){
if($stmt = $this->mysqli->prepare("SELECT * FROM test WHERE id =?")) {
// some minor changes to the bind and execute statments. I
// wrapped them in an if just to make sure there were no errors
// if i had more time i might make these more elegant rather than just
// echoing them out
/* bind parameters for markers */
if(!($stmt->bind_param('i',$id))) {
echo $stmt->error;
}
/* execute query */
if(!($stmt->execute())) {
echo $stmt->error;
}
// You could also bind the results to specific variables here and return those
//$stmt->bind_result($id,$name,$email);
//$stmt->fetch();
//$result = $name;
//assign the results to a variable and then return that variable
//rather than processing the results here
$result = $stmt->get_result();
return $result;
} else {
// if an error occurs return the error, once again another place for
// improvement but at the very least will show you an error
echo $this->mysqli->error;
}
}
public function update_post($name, $email, $id)
{
$up="UPDATE test SET name=?, email=? WHERE id =?";
// originally had $mysqli->prepare($up), fixed syntax
if($stmt = $this->mysqli->prepare($up))
{
//$stmt->bind_param("sssii", $name, $address,$email,$mob,$id);
$stmt->bind_param("ssi", $name, $email,$id);
// execute was spelled wrong
if($stmt->execute()) {
return true;
} else {
return $stmt->error;
//return false;
}
} else {
return false;
}
}
}
// set up database connection
$connect_dbase = new connect_dbase();
if($connect_dbase->connection()) {
// if connection was successful, call display_all
// and assign the results to $result
$result = $connect_dbase->display_all(2);
// you could do a foreach here also but since there
// was only one result i just echoed the values
while($row = $result->fetch_array()) {
echo $row['id'] . "<br/>";
echo $row['name'] . "<br/>";
echo $row['email'] . "<br/>";
}
// then call update_post
$update_result = $connect_dbase->update_post("asdf","asdf@yahoo.com",2);
// show a message if the update_post was successful
if($update_result) {
echo "Update successful";
}
}
?>