im trying to use mysqli with bind_result but all i get is null values. My $stmt
number of rows is greater than 0 so i do have some data in it.
I dont realy understand what value should come into bind_result
I have read at the manual http://php.net/manual/en/mysqli-stmt.bind-result.php
And they dont explain what should i put in the bind_result.
Should i put there the column names? if yes, as strings? how do i get my wanted values?
Here is my code thanks for helping:
$sql = "SELECT * FROM comments WHERE workout_name = ? AND user = ?";
$stmt = $mysqli->prepare($sql) or trigger_error($mysqli->error."[$sql]");
$stmt->bind_param('ss', $workout_name, $user);
$workout_name = "rytg";
$user = "tomer";
$stmt->execute();
$stmt->store_result();
$stmt->bind_result($comment, $commented_user);
if($stmt->num_rows > 0)
{
$response["workouts"] = array();
while ($stmt->fetch())
{
// temp user array
$workouts = array();
$workouts["comment"] = $comment;
$workouts["user"] = $commented_user;
// push single product into final response array
array_push($response["workouts"], $workouts);
}
}
Your only problem is insufficient error reporting
error_reporting(E_ALL);
ini_set('display_errors',1);
Just add these lines at the top of your code and you will be immediately informed of the exact problem with your code.
Note that on the production server you have to turn displaying errors off and logging on
I don't have a working PHP installation next to me at the moment, so I can't verify it, but I believe you might have to bind both parameters and result before you execute the query, like so:
$workout_name = "rytg";
$user = "tomer";
$stmt = $mysqli->prepare($sql) or trigger_error($mysqli->error."[$sql]");
$stmt->bind_param('ss', $workout_name, $user);
$stmt->bind_result($comment, $commented_user);
$stmt->execute();
I'm not too sure about store_result() either. I don't recall having to use it while retrieving the results, so you might want to try running your code without it and see what happens.
Related
I have a mysqli database object $DataBase and the following code works as intended:
$stmt = $DataBase->stmt_init();
$stmt->prepare("UPDATE `optshop_stock` SET quantity_b = ? WHERE product_id = ?;");
$stmt->bind_param('ii', $qty, $sku);
$stmt->execute();
$stmt->close();
But when I add:
echo $stmt->affected_rows;
between $stmt->execute() and $stmt->close() no value is echoed, not even a zero if nothing happened. Am I using this statement in a correct manner?
( I followed this http://php.net/manual/en/mysqli-stmt.affected-rows.php example)
The property can be retrieved at database level (reference here):
echo $DataBase->affected_rows;
I think you should try to add $stmt->store_result() after $stmt->execute(), otherwise you can't get right results when use $stmt->affected_rows
Would someone please me with the code below, I am inexperienced in this area and my class in SQL was "A long time ago in a galaxy far, far away..." I know the connection string works because I have used it in other functions with this app. I have even used the code below for retrieving *rows from another table in another function, for the most part, except that I didn't use the WHERE clause.
First, I am able to store IP addresses in the table using a function and it is working well. Now I want to check to see if a given one exist in this table. Partial code is given below.
What seems to always return is 0 rows. I have put in test data into the table and hard-coded the $ipA, but I still get 0 rows return. Please help if possible and thanks for the effort spent.
function checkDB($ipA) {
require_once('connection.inc.php');
$resultAns = "";
//create db connection
$conn = dbConnect();
//init prepared stmt
$stmt = $conn->stmt_init();
//Set sql query for ipAddress search
//prepare the SQL query
$sql = 'SELECT * FROM ipAddress WHERE ipA = ?';
//submit the query and capture the result
if ($stmt->prepare($sql)) {
$stmt->bind_param('s', $ipA);
$stmt = $stmt->execute();
//if qry triggers error affeted_rows value becomes -1 &
//php treats -1 as true; so test for greater than 0
$numRows = $stmt->num_rows; //not to sure about the syntax here
}
// I want to know if the query brought back something or not, I don't what
// to know exactly what, only that it found a match or did not find a match.
// echos are for testing purposes to show me where I am landing.
if ($numRows == 0) {
echo '<script type="text/javascript">window.alert("numRows = 0")</script>';
$resultAns = 0;
} elseif ($numRows == 1) {
echo '<script type="text/javascript">window.alert("numRows = 1")</script>';
$resultAns = 1;
}
return $resultAns;
}
Try storing the result after you execute
$stmt->store_result();
Use $stmt->store_result(); before you call num_rows.
While the others caught one reason that $numRows would never receive a value other than 0, the other piece of code that was flawed and caused problems was...
$stmt = $stmt->execute(); which should have been just $stmt->execute();
I must have mixed it up with other code I wrote from somewhere else.
Thanks for the answers, they did help.
Below is some poorly written and heavily misunderstood PHP code with no error checking. To be honest, I'm struggling a little getting my head around the maze of PHP->MySQLi functions! Could someone please provide an example of how one would use prepared statements to collect results in an associative array whilst also getting a row count from $stmt? The code below is what I'm playing around with. I think the bit that's throwing me off is using $stmt values after store_result and then trying to collect an assoc array, and I'm not too sure why...
$mysqli = mysqli_connect($config['host'], $config['user'], $config['pass'], $config['db']);
$stmt = $mysqli->prepare("SELECT * FROM licences WHERE generated = ?");
$stmt->bind_param('i', $core['id']);
$result = $stmt->execute();
$stmt->store_result();
if ($stmt->num_rows >= "1") {
while($data = $result->fetch_assoc()){
//Loop through results here $data[]
}
}else{
echo "0 records found";
}
I feel a little cheeky just asking for code, but its a working demonstration of my circumstances that I feel I need to finally understand what's actually going on. Thanks a million!
I searched for a long time but never found documentation needed to respond correctly, but I did my research.
$stmt->get_result() replace $stmt->store_result() for this purpose.
So, If we see
$stmt_result = $stmt->get_result();
var_dump($stmt_result);
we get
object(mysqli_result)[3]
public 'current_field' => int 0
public 'field_count' => int 10
public 'lengths' => null
public 'num_rows' => int 8 #That we need!
public 'type' => int 0
Therefore I propose the following generic solution. (I include the bug report I use)
#Prepare stmt or reports errors
($stmt = $mysqli->prepare($query)) or trigger_error($mysqli->error, E_USER_ERROR);
#Execute stmt or reports errors
$stmt->execute() or trigger_error($stmt->error, E_USER_ERROR);
#Save data or reports errors
($stmt_result = $stmt->get_result()) or trigger_error($stmt->error, E_USER_ERROR);
#Check if are rows in query
if ($stmt_result->num_rows>0) {
# Save in $row_data[] all columns of query
while($row_data = $stmt_result->fetch_assoc()) {
# Action to do
echo $row_data['my_db_column_name_or_ALIAS'];
}
} else {
# No data actions
echo 'No data here :(';
}
$stmt->close();
$result = $stmt->execute(); /* function returns a bool value */
reference : http://php.net/manual/en/mysqli-stmt.execute.php
so its just sufficient to write $stmt->execute(); for the query execution.
The basic idea is to follow the following sequence :
1. make a connection. (now while using sqli or PDO method you make connection and connect with database in a single step)
2. prepare the query template
3. bind the the parameters with the variable
4. (set the values for the variable if not set or if you wish to change the values) and then Execute your query.
5. Now fetch your data and do your work.
6. Close the connection.
/*STEP 1*/
$mysqli = mysqli_connect($servername,$usrname,$pswd,$dbname);
/*STEP 2*/
$stmt = $mysqli->prepare("SELECT * FROM licences WHERE generated = ?");
/*Prepares the SQL query, and returns a statement handle to be used for further operations on the statement.*/
//mysqli_prepare() returns a statement object(of class mysqli_stmt) or FALSE if an error occurred.
/* STEP 3*/
$stmt->bind_param('i', $core['id']);//Binds variables to a prepared statement as parameters
/* STEP 4*/
$result = $stmt->execute();//Executes a prepared Query
/* IF you wish to count the no. of rows only then you will require the following 2 lines */
$stmt->store_result();//Transfers a result set from a prepared statement
$count=$stmt->num_rows;
/*STEP 5*/
//The best way is to bind result, its easy and sleek
while($data = $stmt->fetch()) //use fetch() fetch_assoc() is not a member of mysqli_stmt class
{ //DO what you wish
//$data is an array, one can access the contents like $data['attributeName']
}
One must call mysqli_stmt_store_result() for (SELECT, SHOW, DESCRIBE, EXPLAIN), if one wants to buffer the complete result set by the client, so that the subsequent mysqli_stmt_fetch() call returns buffered data.
It is unnecessary to call mysqli_stmt_store_result() for other queries, but if you do, it will not harm or cause any notable performance in all cases.
--reference: php.net/manual/en/mysqli-stmt.store-result.php
and http://www.w3schools.com/php/php_mysql_prepared_statements.asp
One must look up the above reference who are facing issue regarding this,
My answer may not be perfect, people are welcome to improve my answer...
If you would like to collect mysqli results into an associative array in PHP you can use fetch_all() method. Of course before you try to fetch the rows, you need to get the result with get_result(). execute() does not return any useful values.
For example:
<?php
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$mysqli = new mysqli($config['host'], $config['user'], $config['pass'], $config['db']);
$mysqli->set_charset('utf8mb4'); // Don't forget to set the charset!
$stmt = $mysqli->prepare("SELECT * FROM licences WHERE generated = ?");
$stmt->bind_param('i', $core['id']);
$stmt->execute(); // This doesn't return any useful value
$result = $stmt->get_result();
$data = $result->fetch_all(MYSQLI_ASSOC);
if ($data) {
foreach ($data as $row) {
//Loop through results here
}
} else {
echo "0 records found";
}
I am not sure why would you need num_rows, you can always use the array itself to check if there are any rows. An empty array is false-ish in PHP.
Your problem here is that to do a fetch->assoc(), you need to get first a result set from a prepared statement using:
http://php.net/manual/en/mysqli-stmt.get-result.php
And guess what: this function only works if you are using MySQL native driver, or "mysqlnd". If you are not using it, you'll get the "Fatal error" message.
You can try this using the mysqli_stmt function get_result() which you can use to fetch an associated array. Note get_result returns an object of type mysqli_result.
$stmt->execute();
$result = $stmt->get_result(); //$result is of type mysqli_result
$num_rows = $result->num_rows; //count number of rows in the result
// the '=' in the if statement is intentional, it will return true on success or false if it fails.
if ($result_array = $result->fetch_assoc(MYSQLI_ASSOC)) {
//loop through the result_array fetching rows.
// $ rows is an array populated with all the rows with an associative array with column names as the key
for($j=0;$j<$num_rows;$j++)
$rows[$j]=$result->fetch_row();
var_dump($rows);
}
else{
echo 'Failed to retrieve rows';
}
I must be missing something really obvious or am maybe doing things in completely the wrong way, but I've been looking at this for ages and can't see what I'm doing wrong.
I'm just trying to retrieve a record from a table. It's not hard; it's just not working!
my code is
$sql = $db->prepare("SELECT * FROM user WHERE user_name=? AND user_pass=?");
$sql->bind_param('ss', $username, $password);
$result = $sql->execute();
echo "<!-- rows = $result->num_rows -->\n";
just accept that $db IS a valid connection and there are also error checking statements in the actual code. The problem is that it's not finding a row and it's not returning an error, in fact $result->num_rows isn't even zero; it's just empty.
The following code works perfectly...
$sql = "SELECT * FROM user WHERE user_name='$username' AND user_pass='$password'";
$res = $db->query($sql);
echo "<!-- rows = $res->num_rows -->\n";
So what am I doing wrong?
`
The mysqli_stmt execute method returns a boolean. To get the number of rows use $sql->num_rows instead of $res->num_rows.
There seems to be so much confusion and wrong information out there about using SELECT with prepared statements. Using documentation from us3.php.net caused me to try using a function which simply doesn't exist!
The thing I seem to be missing was a store_result statement so the logic goes more like...
$sql = $db->prepare("SELECT * FROM user WHERE user_name=? AND user_pass=?");
$sql->bind_param('ss', $username, $password);
$sql->execute();
$sql->store_result();
echo "<!-- rows = $sql->num_rows -->\n";
I hope this helps someone else who is trying to get this simplest of operations working!
I've still not worked out how (or if) I can do something like $row = $something->fetch_object() or if I'm stuck with having to use bind_result for ALL my table columns but at keast this gets me past the problem of my login page.
i'm having a hard time trying to retrieve data from a table using PDO prepared statements,
Below is my code which isn't working, $post is always empty.
//connection to db has been made
$stmt = $db->prepare("SELECT * FROM posts WHERE id = ?");
$stmt->bindValue(1,$_GET['id']);
$post = $stmt->fetchAll(PDO::FETCH_ASSOC);
$stmt->execute();
I'm quite confident the problem occurs in the third line, so please let me know if there is another way to get the data rather than fetchAll(PDO::FETCH_ASSOC).
Thanks alot.
You're not actually executing the method, but otherwise, your code looks fine!
// Assuming $_GET['id'] has a value (thanks Mike!)
$stmt = $db->prepare("SELECT * FROM posts WHERE id = ?");
$stmt->bindValue(1, $_GET['id']);
$stmt->execute();
$post = $stmt->fetchAll(PDO::FETCH_ASSOC);
As an aside, I'd also make sure that $_GET['id'] is valid; is_int($_GET['id']) returns a boolean that could help.
After fetching your posts, make sure to iterate through them.
if($post != null && count($post) > 0) {
for($i = 0; $i < count($post); $i++) {
echo $post[$i]['title'] . '<br />';
}
}