This question already has answers here:
mysqli query results to show all rows
(4 answers)
Closed 6 years ago.
I am trying for getting multiple records from database but when I try for more then one records. I always getting empty.
First I try FROM DbOperation.php:
public function getDayListByDate($DateString){
$stmt = $this->con->prepare("SELECT DateString FROM gk_eng WHERE DateString= ?");
$stmt->bind_param("s",$DateString);
$stmt->execute();
$result = $stmt->get_result();
return $result;
}
php data get
<?php
require_once 'DbOperation.php';
$db = new DbOperation();
$DateString = $_POST['DateString'];
$devices = $db->getDayListByDate($DateString);
$response = array();
$response['error'] = false;
$response['devices'] = array();
while($device = $devices->fetch_assoc()){
$temp = array();
$temp['Question']=$device['Question'];
$temp['Option_2']=$device['DateString'];
array_push($response['devices'],$temp);
}
echo json_encode($response);
Response: {"error":false,"devices":[{"Question":null,"Option_2":"10/1/2016 12:00:00 AM"},{"Question":null,"Option_2":"10/1/2016 12:00:00 AM"},{"Question":null,"Option_2":"10/1/2016 12:00:00 AM"}{"Question":null,"Option_2":"10/1/2016 12:00:00 AM"}]}
But when I trying for all records and change database query for getting Question field in reponse like.
public function getDayListByDate($DateString){
$stmt = $this->con->prepare("SELECT * FROM gk_eng WHERE DateString= ?");
$stmt->bind_param("s",$DateString);
$stmt->execute();
$result = $stmt->get_result();
return $result;
}
I am getting result empty like "".
I am using for connection
function connect()
{
//Including the constants.php file to get the database constants
include_once dirname(__FILE__) . '/Config.php';
//connecting to mysql database
$this->con = new mysqli(DB_HOST, DB_USERNAME, DB_PASSWORD, DB_NAME);
//Checking if any error occured while connecting
if (mysqli_connect_errno()) {
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
//finally returning the connection link
return $this->con;
}
I think the way you are binding is incorrect too:
public function getDayListByDate($DateString){
$stmt = $this->con->prepare("SELECT * FROM gk_eng WHERE DateString= :DS");
$stmt->bind_param(":DS",$DateString);
$stmt->execute();
$result = $stmt->fetchAll();
return $result;
}
Try This
function getDayListByDate($DateString) {
$result = $this->con->query("SELECT * FROM gk_eng WHERE DateString='$DateString' ");
return $result;
}
you can get answer.. if didnt get ans .. let me know
Related
This question already has answers here:
Why does this PDO statement silently fail?
(2 answers)
Closed 2 years ago.
I receive this error:
Fatal error: Call to a member function fetch() on boolean in
C:\xampp\htdocs\repo\generator\model\database.php on line 34
When I run this code:
class database
{
private $user = 'root';
private $pass = '';
public $pdo;
public function connect() {
try {
$this->pdo = new PDO('mysql:host=localhost; dbname=generatordatabase', $this->user, $this->pass);
echo 'Połączenie nawiązane!';
}
catch(PDOException $e) {
echo 'Połączenie nie mogło zostać utworzone: ' . $e->getMessage();
}
}
public function createTable() {
$q = $this->pdo -> query('SELECT * FROM article');
while($row = $q->fetch()) {
echo $row['id'].' ';
}
$q->closeCursor();
}
}
?>
As per the PHP manual for PDO::query
PDO::query() returns a PDOStatement object, or FALSE on failure.
It looks like your query is failing (on line 33) and thus returning a BOOLEAN (false), likely because at that point in execution, PDO has not connected to a database that contains a table called article. In the connect() method I see that it tries to connect to a db called 'generatordatabase'; ensure this connection is being made prior to calling createTable(), otherwise ensure that it contains a table called 'article'.
I would recommend adding some more code examples, for instance the code that calls this class/method before the error is triggered.
Some error handling will help you avoid issues like this:
$q = $this->pdo->query('SELECT * FROM article');
//error case
if(!$q)
{
die("Execute query error, because: ". print_r($this->pdo->errorInfo(),true) );
}
//success case
else{
//continue flow
}
I'm not sure wheatear this is exactly the error I struggled with, but my error was due to my $con variable, I used a single $con for 2 SQL statements, for example:
$con = new mysqli($host,$username,$password,$database);
$sql = "SELECT name FROM users WHERE email = '$email'";
$stm = $con->prepare($sql);
$stm->execute();
and
$sql1 = "INSERT INTO posts
VALUES('$email','$body')";
$stm1 = $con->prepare($sql1);
if ($stm1->execute()) {
I should have done:
$con = new mysqli($host,$username,$password,$database);
$sql = "SELECT name FROM users WHERE email = '$email'";
$stm = $con->prepare($sql);
$stm->execute();
and
$con1 = new mysqli($host,$username,$password,$database);
$sql1 = "INSERT INTO posts
VALUES('$email','$body')";
$stm1 = $con1->prepare($sql1);
$stm1->execute()
I have a SQL table (modules) with two columns (id, name). Now I can retrieve the rows from this through a PHP script but what I want is to use the value of id as the key, and the value of name as the value, in a multidimensional array. Then I want to be able to encode those into a JSON, retaining the relationship between key/value. I've muddled something together but it returns null.
the relevant code from index.php
$mod1 = $core["module1"];
$mod2 = $core["module2"];
$modules = $db->getModulesById($mod1, $mod2); //module names & ids
$response["module"]["mod1"] = $modules[$mod1];
$response["module"]["mod2"] = $modules[$mod2];
$response["module"]["mod1name"] = $modules[$mod1]["name"];
$response["module"]["mod2name"] = $modules[$mod2]["name"];
echo json_encode($response);
The function from DB_Functions.php
public function getModulesById($mod1, $mod2) {
require_once 'include/Config.php';
$con = mysqli_connect(DB_HOST, DB_USER, DB_PASSWORD);
// Check connection
if (!$con)
{
die("Connection error: " . mysqli_connect_error());
}
// selecting database
mysqli_select_db($con, DB_DATABASE) or die(mysqli_connect_error());
$query = "SELECT * FROM modules WHERE id= '$mod1' OR id='$mod2'";
$result = mysqli_query($con, $query);
$arr = array();
while($row = mysqli_fetch_assoc($result)) {
// process each row
//each element of $arr now holds an id and name
$arr[] = $row;
}
// return user details
return mysqli_fetch_array($arr);
close();
}
I've looked around but I'm just not 'getting' how the query return is then broken down into key/value for a new array. If someone could ELI5 I'd appreciate it. I'm just concerned with this aspect, it's a personal project so I'm not focusing on security issues as yet, thanks.
You are pretty well there
public function getModulesById($mod1, $mod2) {
require_once 'include/Config.php';
$con = mysqli_connect(DB_HOST, DB_USER, DB_PASSWORD, DB_DATABASE);
// Check connection
if (!$con) {
die("Connection error: " . mysqli_connect_error());
}
$query = "SELECT * FROM modules WHERE id= '$mod1' OR id='$mod2'";
$result = mysqli_query($con, $query);
$arr = array();
while($row = mysqli_fetch_assoc($result)) {
$arr[] = $row;
}
// here is wrong
//return mysqli_fetch_array($arr);
// instead return the array youy created
return $arr;
}
And call it and then just json_encode the returned array
$mod1 = $core["module1"];
$mod2 = $core["module2"];
$modules = $db->getModulesById($mod1, $mod2); //module names & ids
$response['modules'] = $modules;
echo json_encode($response);
You should really be using prepared and paramterised queries to avoid SQL Injection like this
public function getModulesById($mod1, $mod2) {
require_once 'include/Config.php';
$con = mysqli_connect(DB_HOST, DB_USER, DB_PASSWORD, DB_DATABASE);
// Check connection
if (!$con) {
die("Connection error: " . mysqli_connect_error());
}
$sql = "SELECT * FROM modules WHERE id= ? OR id=?";
$stmt = $con->prepare($sql);
$stmt->bind_param('ii', $mod1, $mod2);
$stmt->execute();
$result = $stmt->get_result();
$arr = array();
while($row = mysqli_fetch_assoc($result)) {
$arr[] = $row;
}
// here is wrong
//return mysqli_fetch_array($arr);
// instead return the array youy created
return $arr;
}
mysqli_fetch_array requires the result of a mysqli_query result. Passing the constructed array to mysqli_fetch_array() is not going to work.
If you want to have a specific value from a row to use as its key, you can't resolve this with any mysqli_* function. You could however construct it yourself:
while($row = mysqli_fetch_assoc($result)) {
// process each row
//each element of $arr now holds an id and name
$arr[$row['id']] = $row;
}
mysqli_close($con);
return $arr;
You should close the connection before returning the result, code positioned after a return will not be executed.
This question already has answers here:
Why does this PDO statement silently fail?
(2 answers)
Closed 2 years ago.
I receive this error:
Fatal error: Call to a member function fetch() on boolean in
C:\xampp\htdocs\repo\generator\model\database.php on line 34
When I run this code:
class database
{
private $user = 'root';
private $pass = '';
public $pdo;
public function connect() {
try {
$this->pdo = new PDO('mysql:host=localhost; dbname=generatordatabase', $this->user, $this->pass);
echo 'Połączenie nawiązane!';
}
catch(PDOException $e) {
echo 'Połączenie nie mogło zostać utworzone: ' . $e->getMessage();
}
}
public function createTable() {
$q = $this->pdo -> query('SELECT * FROM article');
while($row = $q->fetch()) {
echo $row['id'].' ';
}
$q->closeCursor();
}
}
?>
As per the PHP manual for PDO::query
PDO::query() returns a PDOStatement object, or FALSE on failure.
It looks like your query is failing (on line 33) and thus returning a BOOLEAN (false), likely because at that point in execution, PDO has not connected to a database that contains a table called article. In the connect() method I see that it tries to connect to a db called 'generatordatabase'; ensure this connection is being made prior to calling createTable(), otherwise ensure that it contains a table called 'article'.
I would recommend adding some more code examples, for instance the code that calls this class/method before the error is triggered.
Some error handling will help you avoid issues like this:
$q = $this->pdo->query('SELECT * FROM article');
//error case
if(!$q)
{
die("Execute query error, because: ". print_r($this->pdo->errorInfo(),true) );
}
//success case
else{
//continue flow
}
I'm not sure wheatear this is exactly the error I struggled with, but my error was due to my $con variable, I used a single $con for 2 SQL statements, for example:
$con = new mysqli($host,$username,$password,$database);
$sql = "SELECT name FROM users WHERE email = '$email'";
$stm = $con->prepare($sql);
$stm->execute();
and
$sql1 = "INSERT INTO posts
VALUES('$email','$body')";
$stm1 = $con->prepare($sql1);
if ($stm1->execute()) {
I should have done:
$con = new mysqli($host,$username,$password,$database);
$sql = "SELECT name FROM users WHERE email = '$email'";
$stm = $con->prepare($sql);
$stm->execute();
and
$con1 = new mysqli($host,$username,$password,$database);
$sql1 = "INSERT INTO posts
VALUES('$email','$body')";
$stm1 = $con1->prepare($sql1);
$stm1->execute()
I am trying to make this query using PDO and it is returning and error.I have already verified the connection to the database.
function temperaturaMedia($data_inicio,$data_final,$ema)
{
$db = 'sensorzapp_db';
$query = "SELECT
DATE(DTM) AS 'Dia',
ROUND(AVG(TMP),1) AS 'Temp. Med.'
FROM dados_meteo
WHERE POM = '$ema'
AND DATE(DTM) BETWEEN '$data_inicio' AND '$data_final'
GROUP BY DATE(DTM)";
$stmt = $db->query($query);
return $stmt->fetchAll(PDO::FETCH_ASSOC);
}
You are trying to execute a query on a string, you need to connect to the database, like this:
function temperaturaMedia($data_inicio,$data_final,$ema)
{
try {
$db = new PDO("mysql:host=localhost;dbname=sensorzapp_db","user","password");
} catch($ex) { die("Connection failed"); } // To not disclosure username & password when connection fails (look at the red box on http://www.php.net/manual/de/pdo.connections.php)
$query = "SELECT
DATE(DTM) AS 'Dia',
ROUND(AVG(TMP),1) AS 'Temp. Med.'
FROM dados_meteo
WHERE POM = '$ema'
AND DATE(DTM) BETWEEN '$data_inicio' AND '$data_final'
GROUP BY DATE(DTM)";
$stmt = $db->query($query);
return $stmt->fetchAll(PDO::FETCH_ASSOC);
}
i'm building an website using php and html, im used to receiving data from a database, aka Dynamic Website, i've build an CMS for my own use.
Im trying to "simplify" the receiving process using php and functions.
My Functions.php looks like this:
function get_db($row){
$dsn = "mysql:host=".$GLOBALS["db_host"].";dbname=".$GLOBALS["db_name"];
$dsn = $GLOBALS["dsn"];
try {
$pdo = new PDO($dsn, $GLOBALS["db_user"], $GLOBALS["db_pasw"]);
$stmt = $pdo->prepare("SELECT * FROM lp_sessions");
$stmt->execute();
$row = $stmt->fetchAll();
foreach ($row as $row) {
echo $row['session_id'] . ", ";
}
}
catch(PDOException $e) {
die("Could not connect to the database\n");
}
}
Where i will get the rows content like this: $row['row'];
I'm trying to call it like this:
the snippet below is from the index.php
echo get_db($row['session_id']); // Line 22
just to show whats in all the rows.
When i run that code snippet i get the error:
Notice: Undefined variable: row in C:\wamp\www\Wordpress ish\index.php
on line 22
I'm also using PDO just so you would know :)
Any help is much appreciated!
Regards
Stian
EDIT: Updated functions.php
function get_db(){
$dsn = "mysql:host=".$GLOBALS["db_host"].";dbname=".$GLOBALS["db_name"];
$dsn = $GLOBALS["dsn"];
try {
$pdo = new PDO($dsn, $GLOBALS["db_user"], $GLOBALS["db_pasw"]);
$stmt = $pdo->prepare("SELECT * FROM lp_sessions");
$stmt->execute();
$rows = $stmt->fetchAll();
foreach ($rows as $row) {
echo $row['session_id'] . ", ";
}
}
catch(PDOException $e) {
die("Could not connect to the database\n");
}
}
Instead of echoing the values from the DB, the function should return them as a string.
function get_db(){
$dsn = "mysql:host=".$GLOBALS["db_host"].";dbname=".$GLOBALS["db_name"];
$dsn = $GLOBALS["dsn"];
$result = '';
try {
$pdo = new PDO($dsn, $GLOBALS["db_user"], $GLOBALS["db_pasw"]);
$stmt = $pdo->prepare("SELECT * FROM lp_sessions");
$stmt->execute();
$rows = $stmt->fetchAll();
foreach ($rows as $row) {
$result .= $row['session_id'] . ", ";
}
}
catch(PDOException $e) {
die("Could not connect to the database\n");
}
return $result;
}
Then call it as:
echo get_db();
Another option would be for the function to return the session IDs as an array:
function get_db(){
$dsn = "mysql:host=".$GLOBALS["db_host"].";dbname=".$GLOBALS["db_name"];
$dsn = $GLOBALS["dsn"];
$result = array();
try {
$pdo = new PDO($dsn, $GLOBALS["db_user"], $GLOBALS["db_pasw"]);
$stmt = $pdo->prepare("SELECT * FROM lp_sessions");
$stmt->execute();
$rows = $stmt->fetchAll();
foreach ($rows as $row) {
$result[] = $row['session_id'];
}
}
catch(PDOException $e) {
die("Could not connect to the database\n");
}
return $result;
}
Then you would use it as:
$sessions = get_db(); // $sessions is an array
and the caller can then make use of the values in the array, perhaps using them as the key in some other calls instead of just printing them.
As antoox said, but a complete changeset; change row to rows in two places:
$rows = $stmt->fetchAll();
foreach ($rows as $row) {
echo $row['session_id'] . ", ";
}
Putting this at the start of the script after <?php line will output interesting warnings:
error_reporting(E_ALL|E_NOTICE);
To output only one row, suppose the database table has a field named id and you want to fetch row with id=1234:
$stmt = $pdo->prepare("SELECT * FROM lp_sessions WHERE id=?");
$stmt->bindValue(1, "1234", PDO::PARAM_STR);
I chose PDO::PARAM_STR because it will work with both strings and integers.