I am using PDO for the first time. I created this method, and I am getting this error:
Call to a member function rowCount() on a non-object
The following is my code.
$db = new PDO("mysql:host=$dbhost;dbname=$dbname;charset=utf8", $dbuser, $dbpassword)
function doesRecordExist($query) {
global $db;
try {
$stmt = $db->query($query);
$count = $stmt->rowCount();
return $count;
} catch (PDOException $ex) {
die($ex->getMessage());
}
}
Can you help me please
Why not use prepared statements: Plus you need to execute you query before you count it
$db = new PDO("mysql:host=$dbhost;dbname=$dbname;charset=utf8", $dbuser, $dbpassword)
function doesRecordExist($query) {
global $db;
try {
$stmt = $db->prepare($query);
$stmt->execute();
$count = $stmt->rowCount();
return $count;
} catch (PDOException $ex) {
die($ex->getMessage());
}
}
Don't use a global variable. Pass this one as an object instead.
$db = new PDO(....);
function doesRecordExist($query, PDO $db) {
try {
$stmt = $db->prepare($query);
$stmt->execute();
...
I forgot to create a table that the query was referring to. Sorry for any inconveniences
Related
I wonder whats the problem in my code? I tried all the sources I can search but it still gives me the same error which is still "Call to a member function bind_Param() on a non-object".here's my code.,hope someone can help me, thanks
$app->get('/students/:student_id',function () use($app){
$sql = "SELECT * FROM students WHERE student_id =:student_id";
try {
$db = connect_db();
$stmt = $db->prepare($sql);
$stmt->bind_Param("student_id", $student_id);
$stmt->execute();
$students = $stmt->fetchObject();
$db = null;
echo json_encode($students);
}
catch(PDOException $e) {
echo '{"error":{"text":'. $e->getMessage() .'}}';
}
});
This one works:
$app->get('/students/:student_id', function ($student_id) use($app){
$sql = "SELECT * FROM students WHERE student_id = ?";
try {
$db = connect_db();
$stmt = $db->prepare($sql);
$stmt->bind_Param("i", $student_id);
$stmt->execute();
$result = $stmt->get_result();
$students = $result->fetch_object();
$db = null;
echo json_encode($students);
}
catch(PDOException $e) {
echo '{"error":{"text":'. $e->getMessage() .'}}';
}
});
I assume that you're using this definition of the connect_db function:
function connect_db() {
$dbhost="localhost";
$dbuser="user";
$dbpass="pass";
$dbname="stackoverflow-33750846";
return new mysqli($dbhost, $dbuser, $dbpass, $dbname);;
}
Perhaps there is a bit of confusion using the database connection and read data from it, so I add some points:
Be sure to pass $student_id as a parameter to the callable function;
$stmt->bind_Param accepts a string that represents the type of the parameters and all the binding parameters;
fetchObject is a function of the mysqli_result class.
I'm attempting to use functions to get certain data from database. For example, I want to get info from an user with ID 1.
try {
$connection = new PDO("mysql:host=localhost;dbname=database", "root", "password");
}
catch (PDOException $e) {
die("Error: " . $e->getMessage());
}
$connection->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
function getUser($id) {
global $connection;
$query = $connection->prepare("SELECT * FROM accounts WHERE ID = '$id'");
$query->execute();
while($row = $query->fetch()) {
echo $row['playername'];
$user[] = $row;
}
}
And then in my index.php.
include 'inc/db.php';
getUser("1");
foreach($user AS $user) {
echo $user['ID'];
}
The first echo works, I get the username displayed, but the foreach doesn't echo anything. I tried to var_dump($user); but ended up getting NULL.
You need to have:
function getUser(...) {
...
$user = array();
while(...) {
$user[] = $row;
}
return $user;
}
And then in your main code:
$users = getUser(1);
foreach($users as $user) { .... }
Right now you're defining local variables and then not returning them, so they're lost when the method exits. And then not capturing any possible returned values anyways, making your code basically pointless.
Your problem is that you are writing too much code. PHP can't process so much, chokes and dies.
All you actually need is
$pdo = new PDO("mysql:host=localhost;dbname=database", "root", "password");
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$pdo->setAttribute(ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);
function getUser($id)
{
global $pdo;
$query = $pdo->prepare("SELECT * FROM accounts WHERE ID = ?");
$query->execute(array($id));
return $query->fetch();
}
$user = getUser(1);
echo $user['playername'];
to make it little more serious, you should use prepared statement to pass variable into query and return data from the function.
I'm tinkering with a class that 'should' allow me to easily execute a fetchall query and display the results within a foreach statement. I assume all is working correctly as I have no errors. As for the foreach - this must be the problem? How would I foreach the results gained from the $connect->query()? I'm new to using any database OOP framework in my functions so I could be along the wrong lines completely.
<?
error_reporting(1);
class dbconnect {
private $host;
private $database;
private $username;
private $password;
private $pdo;
private $error;
public function __construct() {
$this->host = "localhost"; // Host
$this->database = "images"; // Database Name
$this->username = "*"; // Username
$this->password = "*"; // Password
$options = array(
PDO::MYSQL_ATTR_INIT_COMMAND => 'SET NAMES utf8'
);
try {
$this->pdo = new PDO("mysql:host={$this->host};dbname={$this->dbname};charset=utf8", $this->username, $this->password, $options);
}
catch(PDOException $e) {
$this->error = $e->getMessage();
}
}
public function query($query) {
try {
$stmt = $this->pdo->prepare($query);
$stmt->execute();
} catch(PDOException $ex) {
die("Failed to run query: " . $ex->getMessage());
}
$rows = $stmt->fetchAll();
return $rows;
}
}
$connect = new dbconnect;
$rows = $connect->query("select * from photos");
foreach($rows as $row):
print $row['id'];
endforeach;
?>
The $rows variable you're declaring inside query is not accessible to the outside, it is local to that function. Most likely, you simply want to return those results to the caller:
$rows = $stmt->fetchAll();
return $rows; // return value from function...
and have the caller capture that return value in its own variable:
$rows = $connect->query("select * from images"); // ... is received by caller
foreach($rows as $row):
Also check out dougjore's answer, you're mixing $this->stmt and $stmt inside your query method.
Pretty sure you aren't ever actually executing the query:
$this->stmt = $this->pdo->prepare($query);
$stmt->execute();
I believe (I could be wrong, I'm rather new to PDO myself and I haven't built a class for it), that you need to say $this->stmt->execute();
You could do
//PDO::FETCH_ASSOC: returns an array indexed by column name as returned in your result set
$this->stmt = $this->pdo->prepare($query);
$this->stmt->execute();
while ($result = $this->stmt->fetch(PDO::FETCH_ASSOC))
{
//do something with the result
}
Have a look here for more options to fetch PDO query results:
http://php.net/manual/en/pdostatement.fetch.php
$connect = new dbconnect;
$sql="select * from photos";
$stmt=$connect->pdo->prepare($sql);
$stmt->execute();
$result=$stmt->fetch(PDO::FETCH_ASSOC);
foreach($result as $key => $value) {
echo $key . "-" . $value . "<br/>";
}
i want to get the current max size of my DB. I have found the statements an checked it out. It works fine in VS2012 SQL Explorer. But when im using php im geting no data.
This is my function:
function getLoad() {
$conn = connect();
$string = 'DATABASEPROPERTYEX ( 'database' , 'MaxSizeInBytes' )';
$stmt = $conn->query($string);
return $stmt->fetchAll(PDO::FETCH_NUM);
}
The problem is that i get an error in fetching the $stmt. Error is:
can not fetchAll(11)
This code will print the database edition and max size in GB:
<?php
function get_database_properties($server, $database, $username, $password) {
try {
$conn = new PDO ("sqlsrv:server=tcp:{$server}.database.windows.net,1433; Database={$database}", $username, $password);
$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$conn->setAttribute(constant('PDO::SQLSRV_ATTR_DIRECT_QUERY'), true);
$query = "SELECT CONVERT(NVARCHAR(128), DATABASEPROPERTYEX ('{$database}', 'Edition')) as 'Edition', " .
"CONVERT(DECIMAL,DATABASEPROPERTYEX ('{$database}', 'MaxSizeInBytes'))/1024/1024/1024 AS 'MaxSizeInGB'";
$stmt = $conn->query($query);
$row = $stmt->fetch();
$conn = null;
return $row;
}
catch (Exception $e) {
die(print_r($e));
}
}
$db_properties = get_database_properties("yourserver", "yourdatabase", "youruser", "yourpassword");
print("Edition={$db_properties['Edition']} MaxSizeInGB={$db_properties['MaxSizeInGB']}\n");
?>
I'm trying to convert my codes to PDO from mysql_query, and starting with this function
function label_for_field($field_name, $table_name) {
$table = array();
// Bind variables to parameters
$param_array = array(':bundle' => $table_name, ':field_name' => $field_name);
// Prepare Query Statement
$query = "SELECT data FROM field_config_instance WHERE bundle = :bundle AND field_name = :field_name";
$STH = $DBH -> prepare($query);
// Execute
$STH -> execute($param_array);
// Set the fetch mode
$STH -> setFetchMode(PDO::FETCH_OBJ);
while ($row = $STH -> fetch()) {
$info = unserialize($row -> data);
$table[] = $info['label'];
}
return $table[0];
}
and I'm trying out just output it to see if it works
include_once ("includes/connect.php");
include ("includes/functions.php");
echo label_for_field("field_account_number", "account_table");
And here's the connect.php
// Include Constants
require_once ("constants.php");
//Establish Connection
try {
$DBH = new PDO("mysql:host=$host;dbname=$dbname", $user, $pass);
}
catch (PDOException $e) {
echo $e -> getMessage();
}
I don't know if it's because I'm binding the parameters wrong, it just gave me an server error page
"Server error. The website encountered an error while retrieving ......."
Thanks in advance
You need to set the PDO error mode to produce exceptions before you can catch them.
In your connect.php:
try {
$DBH = new PDO("mysql:host=$host;dbname=$dbname", $user, $pass);
$DBH->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
}
Then you can have a similar try/catch statement in your function to that of your connection file, and use it to show the error in your development environment.
Try this instead to see if you get valid objects returned from the query.
// Prepare Query Statement
$query = "SELECT data FROM field_config_instance WHERE bundle = :bundle AND field_name = :field_name";
$STH = $DBH -> prepare($query);
$STH->bindValue(":bundle", $table_name);
$STH->bindValue(":field_name", $field_name);
$STH->execute();
$STH->setFetchMode (PDO::FETCH_OBJ);
$result = $STH->fetchAll();
var_dump($result);