I'm just trying to select a specific row in the DB, but my result-set keeps coming up empty for some reason. However, when I run the query in HeidiSQL, I get results.
I'm stumped. I don't see anything particularly wrong with my code, and I've tried echoing $mysqli->error, but I don't have any errors. I have also added ini_set('display_errors', 'On'); error_reporting(E_ALL); to my code.
$id =$_GET['sysid'];
$system_info = $mysqli->prepare("SELECT * FROM systems WHERE systems.id = ?");
$system_info->bind_param("i", $id);
$system_info->execute();
$system_info->store_result();
$system_info->bind_result($system_id, $system_name, $system_img);
You need to fetch the results.
$id = $_GET['sysid'];
$system_info = $mysqli->prepare("SELECT * FROM systems WHERE systems.id = ?");
$system_info->bind_param("i", $id);
$system_info->execute();
$system_info->bind_result($system_id, $system_name, $system_img);
$system_info->fetch();
Then you can use $system_id, $system_name and $system_img.
store_result will return you a mysqli_result object; it ignores bind_result.
$id = $_GET['sysid'];
$system_info = $mysqli->prepare("SELECT * FROM systems WHERE systems.id = ?");
$system_info->bind_param("i", $id);
$system_info->execute();
$result = $system_info->store_result();
list($system_id, $system_name, $system_img) = $result->fetch_array(MYSQLI_NUM);
Related
I have been chasing my tale with this for a long time. I have not been able to find an issue with this code:
$query = "SELECT * FROM CUSTOMER WHERE username = ?";
$stmt = $db->prepare($query);
$stmt->bind_param("s", $username);
$stmt->execute();
echo $stmt->num_rows." ".$username;`
The CUSTOMER table in my database has three columns: username, pwd, and email. But nonetheless, no results are returned when I assign the $username variable to a value I know exists in the database. I know it exists because this query
$results = $db->query("SELECT * FROM CUSTOMER WHERE username ='$username'");
echo $results->num_rows;
Displays one row, which is what is expected. Can anybody please tell me why my prepared statement will not produce the correct results? I have tried several variations of quoting, not quoting, hardcoding the variable's value, but nothing works. I am on a university server so I have no control over PHP's or MySQL's settings, but I'm not sure that has anything to do with it. It seems like a coding issue, but I can't see anything wrong with the code.
num_rows will be populated only when you execute $stmt->store_result();.
However, 99.99% of the time you do not need to check num_rows. You can simply get the result with get_result() and use it.
$query = "SELECT * FROM CUSTOMER WHERE username = ?";
$stmt = $db->prepare($query);
$stmt->bind_param("s", $username);
$stmt->execute();
$result = $stmt->get_result();
foreach($result as $row) {
// ...
}
If you really want to get the num_rows, you can still access this property on the mysqli_result class.
$result = $stmt->get_result();
$result->num_rows;
You've executed the query successfully, but not done anything with the result. After $stmt->execute();, you're looking for $stmt->bind_result($result);.
With this, you'll have access to the user's information in the $result variable.
I want to change MySQL to PDO:
$mapa = mysql_fetch_array(mysql_query("select * from mapa where id = ".$postac['mapa']." limit 1"));
$mapa_d = mysql_query("select * from mapa_d where mapa = ".$mapa['id']." ");
PHP:
$_SESSION['postac'] = $_POST['postac'];
try like this so far:
$stmt = $pdo->prepare("SELECT * FROM mapa WHERE id=:mapa");
$stmt->bindValue(':mapa', $postac, PDO::PARAM_STR);
$stmt->EXECUTE();
$postac = $stmt->fetchAll(PDO::FETCH_ASSOC);
mysql update:
mysql_query("update postac set logged = 1 where id = ".$_SESSION['postac']." limit 1");
PDO:
$stmt = $pdo->prepare("update postac set logged = 1 where id:postac");
$stmt->bindValue(':postac', $_SESSION, PDO::PARAM_STR);
$stmt->EXECUTE();
$_SESSION = $stmt->fetchAll(PDO::FETCH_ASSOC);
Does not work.
Pre-Answer Note:
I assume you have already set up a PDO connection construct ($pdo) before trying to run your PDO queries.
$mapa = mysql_fetch_array(
mysql_query("select * from mapa WHERE id = ".$postac['mapa']." limit 1"));
$mapa_d = mysql_query("select * from mapa_d WHERE mapa = ".$mapa['id']." ");
PHP:
$_SESSION['postac'] = $_POST['postac'];
try like this so far:
$stmt = $pdo->prepare("SELECT * FROM mapa WHERE id=:mapa");
$stmt->bindValue(':mapa', $postac, PDO::PARAM_STR);
$stmt->EXECUTE();
$postac = $stmt->fetchAll(PDO::FETCH_ASSOC);
PART 1:
Be Consistent
Your original statement uses a value $postac['mapa'] as an id reference in the MySQL_ query, but then your PDO statement you are passing the whole array as a value into the PDO query.
First, MySQL: id ==> $postac['mapa']
Second, PDO: id ==> $postac
So this is causing an immediate issue as you're passing a whole array in to PDO which is somehow expected to extract one value from this array. This array is being classed as a string with your PDO::PARAM_STR declaration so this is preventing the query from using this value, as it doesn't fit what it's told to expect.
Therefore this returns a NULL query.
So to fix it,
$stmt = $pdo->prepare("SELECT * FROM mapa WHERE id=:mapa");
$stmt->bindValue(':mapa', $postac['mapa'], PDO::PARAM_STR);
$stmt->execute();
$postac = $stmt->fetchAll(PDO::FETCH_ASSOC);
Part 2:
Syntax
$stmt = $pdo->prepare("update postac set logged = 1 where id:postac");
$stmt->bindValue(':postac', $_SESSION, PDO::PARAM_STR);
$stmt->EXECUTE();
$_SESSION = $stmt->fetchAll(PDO::FETCH_ASSOC);
As above, you're passing the whole $_SESSION array as a PARAM_STR value, so it's returning VOID /NULL. You also have a syntax fault that you're using WHERE id:postac, but you really mean WHERE id = :postac be careful of missing out syntax such as = !!.
PART 3:
Error Checking
It is well worth exploring and learning how to get useful error feedback on PHP PDO, as it will save you posting to StackOverfow X times a day (hopefully!)!
There is a good answer here about how to setup PDO to output errors. It is also well worth browsing the PHP Manual for PDO error checking details.
I'm having a problem running prepared queries on a MSSQL database using PDO. I can connect to the database and run SELECT queries with no parameters, but now I'm trying to run a simple SELECT query with one parameter, :user. However, the code does not return any values, despite the fact that there definitely is a database row with that value in. Here's the code I'm using:
$db = new PDO('dblib:host='.$dbHost.';dbname='.$dbName.';charset=utf8mb4',$dbUser, $dbPass);
$stmt = $db->prepare('SELECT * FROM customer WHERE email_address = :user ');
$stmt->bindValue(":user", $_SESSION["username"], PDO::PARAM_STR);
$result = $stmt->fetchAll(PDO::FETCH_ASSOC);
var_dump($result);
I receive no output from the var_dump. I know that in the database there is a correct row, so I tried:
$stmt = $db->prepare("SELECT * FROM customer WHERE email_address = 'the#email.com'");
$result = $stmt->fetchAll(PDO::FETCH_ASSOC);
var_dump($result);
And yet still no value was returned. Am I doing something wrong with PDO? If I type this exact query into the query bar it runs.
you forgot to execute your query.
right after the paramter binding, put this code:
$stmt->execute();
Ok, I'm an idiot. Forgot to execute the query. Amended code for people in the same predicament:
$db = new PDO('dblib:host='.$dbHost.';dbname='.$dbName.';charset=utf8mb4',$dbUser, $dbPass);
$stmt = $db->prepare('SELECT * FROM customer WHERE email_address = :user ');
$stmt->bindValue(":user", $_SESSION["username"], PDO::PARAM_STR);
$stmt->execute();
$result = $stmt->fetchAll(PDO::FETCH_ASSOC);
var_dump($result);
hope someone can help me.
i have a very simple prepared SELECT statment in PHP:
$query_select = ("SELECT * FROM companies where user_name = ? ");
$stmt = $mysqli->prepare($query_select);
$stmt->bind_param("s", $user_name);
$stmt->execute();
$count = $stmt->num_rows;
in companies table I have several rows with the $user_name i`m trying to query. But i still get 0 rows as a result.
The strange thing is that the non PREPARED version works:
$query = 'SELECT * FROM companies WHERE user_name="'.$user_name.'"';
$result = $mysqli->query($query);
$count= $result->num_rows;
echo "Aantal: ".$count;
So my question is, does anyone know why the prepared version returns ZERO and the non prepared version returns the correct number of rows?
Add this line to your code between execute and num_rows statement.
$stmt->store_result();
You have to store it before counting it.
For mysqli prepared statements, you must take an additional step: storing the result.
Try this:
$query_select = ("SELECT * FROM companies where user_name = ? ");
$stmt = $mysqli->prepare($query_select);
$stmt->bind_param("s", $user_name);
$stmt->execute();
$stmt->store_result(); // <-- new line
$count = $stmt->num_rows;
May be you need to bind the result:
/* bind result variables */
$stmt->bind_result($district);
Full example here
I'm having some troubles with the fetch-method. Here's the code:
$stmt = $db->prepare("INSERT INTO x (name) VALUES (:username)");
$stmt->bindParam(':username', $username);
$result = $stmt->execute();
if ($result == '1') {
$id = $stmt->fetch();
return $id;
}
The query is executed and data inserted, and $result is '1'. However, when I try to fetch the result, it's returning false.
Any tips?
You can $db->lastInsertId() in MySQL (apparently it's not dependable, but I've never had a problem with it). Either That or run another query: SELECT LAST_INSERT_ID() and fetch that.
If you're wanting to fetch the number of rows inserted, follow it with this query:
$rows_inserted = $db->query("SELECT FOUND_ROWS()")->fetchColumn();