Systemcrash with mysql-object query in while loop - php

I tried to write my code as short as possible but I discovered something strange here.
If I fetch the query within a 'while loop' the system crashes.
Here's an example.
$sql = 'SELECT * FROM table';
while ($row = $db_ob->query($sql)->fetch_array()){
echo $row['one'];
}
Is this due to my machine or what can I do?
If I write it like my second example, there are no problems
$data = $db_ob->query($sql)->fetch_array()['one'];

This is because you re-run the query on every loop iteration, so it will never end. You need to be sure to only run the query once, then iterate over the results.
$sql = 'SELECT * FROM table';
$result = $db_ob->query($sql);
while ($row = $result->fetch_array()) {
echo $row['one'];
}

Your script execute mysql Query, Retriving datas 'N' times, So you need to rewrite as like,
$sql = 'SELECT * FROM table';
$Result = $db_ob->query($sql);
while ($row = $Result->fetch_array()){
echo $row['one'];
}

Related

Error displaying rows from MySQL tables

I am trying to get rows from a table when a condition is satisfied (status = 'no transit') but nothing shows up even when rows are supposed to show up (count is 1 and more).
if($query['num'] == 0){
echo "<p>No shopping orders on transit</p>";
}else{
$sql = "SELECT *, FORMAT(total, 0) AS total, FORMAT(grand_total, 0) AS grand_total FROM shipping_details WHERE status = 'no transit' ORDER BY order_id DESC";
foreach ($db->query($sql) AS $query){
echo" Show some results ";
$select = "SELECT * FROM shipping_order WHERE order_id = :order_id";
foreach ($db->query($select, array('order_id' => $query['order_id'])) AS $items){
echo"
Some results
";
//Foreach ends
}
}
}
You don't show enough that we can tell which codebase you use to connect to your DB (MySQLi, mysql_, or PDO), so the code below may need some tweaking.
The problem is basically that you never retrieve your database results. Instead you try to loop through the query execution itself.
Change
$sql = "SELECT *...";
foreach ($db->query($sql) AS $query)...
To
$sql = "SELECT *...";
$result = $db->query($sql); //execute the query
if(!$result) die($db->error); //exit and show error if query failed
//now we can fetch the results one at a time and loop through them
//this line may need to be adjusted if you're not using MySQLi
while($row = $result->fetch_assoc())...
Within the while loop, $row will contain the values from the DB record. Use print_r($row) to learn its shape.
It is not working, because you forgot to use prepare and execute methods from pdoStatemnt class.
See below:
$stmt = $db->prepare("SELECT * FROM shipping_order WHERE order_id = :order_id");
$stmt->execute(array('order_id' => $query['order_id']));
while ($result = $stmt->fetch(PDO::FETCH_ASSOC)){
echo"
Some results
";
//Foreach ends
}

incorrect result display from database

I have a database table that has 4 records with a column _id that auto increments. When I run a query to get all records, it works but it doesn't echo out all the ids, it only points to the first rows and echos it four times. I am using PHP and MySQLi. Here is my code
Code for querying
$sql = "SELECT * FROM att_table";
$query = $conn->query($sql);
$result = $query->fetch_assoc();
Code for display
do{
echo result['_id'];
}while($query->fetch_assoc());
It outputs 1111 instead of 1234. Please what is wrong?
You're fetching each of the 4 results, so it loops the appropriate number of times; but you're only assigning the fetched result to $result once, so that's the only _id value that gets echoed
do{
echo $result['_id'];
}while($result = $query->fetch_assoc())
You also can use a foreach loop :
$sql = "SELECT * FROM att_table";
$query = $conn->query($sql);
$result = $query->fetch_assoc();
foreach($result as $data){
echo $data['_id'];
}

PHP loop not performing as it should

$query = "SELECT * FROM table WHERE data = '$userinput'";
$row = mysql_query($query);
while ($row = mysql_fetch_array($row))
{
echo $row['data'];
}
Ok So my questions are:
What exactly does mysql_fetch_array return?
AND if my WHERE clause finds multiple matches, shouldn't the loop execute numerous times?
I am running a program and I can only get the first result to print
You're overwriting $row. Instead use a different variable for the query result.
$query = "SELECT * FROM table WHERE data = '$userinput'";
$result = mysql_query($query);
while ($row = mysql_fetch_array($result))
{
echo $row['data'];
}
Try using mysql_fetch_assoc($row)
You should not use the same variable as the index and the loop variable.
$row = mysql_query
while( $row = ...
Replace the first $row with $result

How to print results in php using AVG and CHAR_LENGTH in MySQL Query

How do I show the results for $wordavg in php. I have done the query in SQL on database after taking out variables so I believe the query is correct but don't know how to show the results of the search in php.
$usertable = 'words';
$yourfield = 'wordname';
$query = "SELECT AVG(CHAR_LENGTH( wordname)) AS $wordavg FROM $usertable WHERE $yourfield LIKE '"."$current_letter"."%' ";
$result = mysql_query($query);
First, you should be using mysqli instead. Back to your question, usually you can iterate over a result with a loop as follows:
while ($row = mysql_fetch_assoc($result)) {
echo $row['field'];
}
More info and examples in the PHP mysql_query doc.
Since you only have one row of data to return, you don't need the loop part. You can simply use
$row = mysql_fetch_assoc($result);
$wordavg = $row['wordavg'];
You shouldn't have the $ in wordavg in your query. It should be just ...AS wordavg FROM...

sql query working in phpmyadmin but not via mysql_query in php

Well first of all I am French so I hope my question will be understandable ;-)
I know some people have already experienced problems with queries in php that worked in phpmyadmin. The thing is that each time (or so) these people had "echo" their queries and copy/paste in phpmyadmin, but as php does not always display spaces it was always the problem.
Actually my problem is different :
if I use the query
$sql = "SELECT * FROM jos_dtregister_invoice_sent";
$query = mysql_query($sql);
$result = mysql_fetch_array($query);
it returns all the rows in both phpmyadmin and my php code, but if I want to look in a different table (with same structure), it just works in phpmyadmin and not via my php code (only one row instead of all of them)
Here is the query not working:
$sql = "SELECT * FROM jos_dtregister_receipt_sent";
$query = mysql_query($sql);
$result = mysql_fetch_array($query);
Perhaps the answer is very simple but I admit this is kind of tricky for me...
Many thanks in advance!
Here is my complete code :
function sendReceipt($row) {
$to = getUserInformation($row,10);
$from = getEventAdminEmailFromEmail($row);
$subject = getEventTitle($row)." - Invoice #".$row["confirmNum"];
$message = $row["userFirstName"]." ".$row["userLastName"]." \n\n".getMessageToSendUser($row);
$headers = "From: ".$from."\r\n";
$sql1 = "SELECT * FROM `jos_dtregister_invoice_sent`";
$query1 = mysql_query($sql1);
echo 'Fetched rows number: '.mysql_num_rows($query1)."<br />";
while($row1 = mysql_fetch_array($query1)) {
echo "Invoice Sent: ".$row1["sent"]."<br />";
}
$sql2 = "SELECT * FROM `jos_dtregister_receipt_sent`";
$query2 = mysql_query($sql2);
echo 'Fetched rows number: '.mysql_num_rows($query2)."<br />";
while($row2 = mysql_fetch_array($query2)) {
echo "Receipt Sent: ".$row2["sent"]."<br />";
}
}
mysql_fetch_array() fetches only a row.The name suggests that it fetches a result row as an array
$sql = "SELECT * FROM jos_dtregister_receipt_sent";
$query = mysql_query($sql) or die(mysql_error());
$result = mysql_fetch_array($query);
Try to execute this. The mysql_error() line will spit out what exactly went wrong when trying to execute the SQL. Post it back here and we can help you a little more.
$sql = "SELECT * FROM jos_dtregister_receipt_sent";
$result = mysql_query($sql);
while($row = mysql_fetch_assoc($result)){
// $row will have your data
}
You need to loop over the results with mysql_fetch_array().
while ($result = mysql_fetch_array($query)) {
print_r($result);
}
Or if you want all your results in one big array ($results):
$results = array();
while ($row = mysql_fetch_array($query)) {
$results[] = $row;
}

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