This is probably not a very difficult question to answer. I'm having trouble with this PHP function I wrote... it returns the rows line by line, but it's returning them incremented by 4 each time. So the the 1st row will output, then the 5th, then the 9th...
function showDatabases() {
# $_GET variables from the URL.
$database = mysql_real_escape_string($_GET['database']);
$table = mysql_real_escape_string($_GET['table']);
$mysqli = new mysqli('127.0.0.1', 'root', '', $database);
$query_one = $mysqli->query("SELECT * from $table");
$num_rows = mysqli_num_rows($query_one);
$num_fields = mysqli_num_fields($query_one);
for ($x = 0; $x < $num_rows; $x++) {
for ($c = 0; $c < $num_fields; $c++) {
$row = mysqli_fetch_row($query_one);
echo($row[$c]." ");
}
echo("<br/>");
}
}
Thanks!
mysqli_fetch_row fetched an entire row and moves the pointer to the following row. You should call it only once per each row; now you are calling it once per column.
That is,
for ($x = 0; $x < $num_rows; $x++) {
$row = mysqli_fetch_row($query_one);
for ($c = 0; $c < $num_fields; $c++) {
echo($row[$c]." ");
}
echo("<br/>");
}
you are complicating things
you can do it with just one loop
$query = "SELECT * from $table";
if ($result = $mysqli->query($query)) {
while ($row = $result->fetch_assoc()) {
echo $row['fieldname']." ";
}
}
I advice you to add order by some time the default order is not the id order.
Related
Apparently, the num_rows property does not work in PDO as it would with mysqli.
Normally, with mysqli, my code would look like this:
<?php
$conn = new mysqli('127.0.0.1','root','mypassword','mydbname');
if($conn->connect_errno){
die("Sorry, could not connect.");
}
$id = 1;
$qry = "SELECT * FROM customers WHERE id = ?";
$getCustomers = $conn->prepare($qry);
$getCustomers->bind_param("i",$id);
$getCustomers->execute();
$result = $getCustomers->get_result();
$count = $result->num_rows;
if($count == 0){
echo "Sorry, there are no results";
}else{
while($row = $result->fetch_object()){
echo $row->id;
echo $row->fname;
echo $row->lname;
echo $row->entry_date;
}
}
?>
How do I create the equivalent with PDO? Here is what I have tried so far:
<?php
try{
$conn = new PDO('mysql:host=127.0.0.1;dbname=mydbname','root','mypassword');
}catch(PDOException $e){
echo $e;
}
$id = 1;
$qry = $conn->prepare("SELECT * FROM customers WHERE id = :id");
$qry->execute([':id'=>$id]);
$rows = $qry->fetchAll(PDO::FETCH_OBJ);
$count = count($rows);
if($count == 0){
echo "Sorry, there are no results for your criteria";
}else{
for($i = 0; $i < $count; $i++){
echo $rows->fname;
}
}
?>
Yeah isn't PDO great ;p no need to count rows when you have already got them.
To loop over your result as you have an array.
Change:
for ($i = 0; $i < $count; $i++){
echo $rows->fname;
}
To:
for ($i = 0; $i < $count; $i++){
echo $rows[$i]->fname;
}
Or better just use a foreach.
foreach ($rows as $row) {
echo $row->fname;
}
The statement
fetchAll(PDO::FETCH_OBJ) returns an array containing all of the result set rows as described here. To get the size of the array use sizeof($count). That should give you the size of the array.
To answer your question specifically. You can use rowCount() to retrieve the number of rows in a result:
$qry = $conn->prepare("SELECT * FROM customers WHERE id = :id");
$qry->execute([':id'=>$id]);
$count = $qry->rowCount();
$rows = $qry->fetchAll(PDO::FETCH_ASSOC); //my personal preference
for($i=0; $i < $count; $i++) {
echo $rows[$i]['fname'];
}
To more closely replicate your mysqli code:
while($row = $qry->fetch(PDO::FETCH_OBJ) {
echo $row->fname;
}
Of course, you should always check $conn->errorCode() after each database execution to ensure something go sideways on you.
UPDATE:
As Lawrence points out, rowCount() does not work with MS SQL Server. An alternative in that case is to use fetchAll() and count().
I have 2 Columns in mysql. valami2 and playerID in table players_extra.
I will the following:
give 3000 coppers for the first row in valami2, then 2500 coppers for the second(then each row -500 coppers until the 5th place)....after the 5th place give 500 until the 10th place. for the CORRECT payerID.
$aseco->console('>> Updating `hetimostfin` counts for all Players...');
$hetimostfin = array();
$line = 0;
$coppers = 3000;
$query = "
SELECT
`playerID`,
COUNT(`valami2`) AS `Count`
FROM `players_extra`
GROUP BY `playerID`;
";
$res2 = mysql_query($query);
if ($res2) {
if (mysql_num_rows($res2) > 0) {
while ($row = mysql_fetch_object($res2)) {
$hetimostfin[$row->playerID] = $row->Count;
}
foreach ($hetimostfin as $id => $count) {
$res2 = mysql_query("
UPDATE `players_extra`
SET `valami2` =(`valami2`+'".$coppers."')
WHERE `playerID` = ". $id ."
");
$line ++;
$coppers=($coppers-500);
if ($line >= 6) {
$coppers=500;
}
if ($line == 10){
break;
}
}
}
}
Try PDO. It's a much better and safer way of interacting with databases for PHP. http://php.net/manual/en/pdo.connections.php
$dbh = new PDO("mysql:host=$host;dbname=$dbname", $user, $pass);
$hetimostfin = array();
$coppers = 3000;
$line = 0;
$query = <<<SQL
SELECT
playerID,
COUNT(valami2) AS `count`
FROM players_extra
GROUP BY playerID;
SQL;
foreach($dbh->query($query, PDO::FETCH_ASSOC) as $row) {
$hetimostfin[[$row['playerID']] = $row['count'];
// execute update statement
$line++;
}
Hi i am querying my db so that i can compare every two rows. ex 1 and 2, then 2 and 3, then 3 and 4. and so on and so forth. but it only compares the first two rows. any ideas? here is my code:
$result = mysql_query("SELECT *FROM attendance ORDER BY pid ASC") or die(mysql_error());
// check for empty result
if (mysql_num_rows($result) > 0) {
// $response["nominees"] = array();
while ($row = mysql_fetch_array($result)) {
// temp user array
$prev_sid = $row["sid"];
$prev_pid = $row["pid"];
$row2 = mysql_fetch_array($result);
if($row2["pid"] == $prev_pid){
if(($row2["sid"] - $prev_sid) == 1){
$attended_elec = mysql_query("SELECT pid FROM election_attendance where election_id = '$election_id'");
if(mysql_num_rows($attended_elec) > 0){
$not_officer = mysql_query("SELECT usertype FROM users WHERE pid = '$prev_pid'");
if(mysql_result($not_officer, 0) == "member"){
// echo "PID" . $prev_pid;
// $nominee["pid"] = $row2["pid"];
$user_details = mysql_query("SELECT *FROM users WHERE pid = '$prev_pid'");
if(mysql_num_rows($user_details) > 0){
$response["nominees"] = array();
while ($row3 = mysql_fetch_array($user_details)) {
$nominee = array();
$nominee["pid"] = $row3["pid"];
$nominee["firstname"] = $row3["firstname"];
$nominee["lastname"] = $row3["lastname"];
$nominee["gender"] = $row3["gender"];
$nominee["contact"] = $row3["contact"];
$nominee["email"] = $row3["email"];
$nominee["address"] = $row3["address"];
$nominee["institution"] = $row3["institution"];
$nominee["points"] = $row3["points"];
$nominee["usertype"] = $row3["usertype"];
// push single product into final response array
array_push($response["nominees"], $nominee);
}
}
}
}
}
}
}
// success
$response["success"] = 1;
// echoing JSON response
echo json_encode($response);
} else {
// no products found
$response["success"] = 0;
$response["message"] = "There is no candidate yet from the records.";
// echo no users JSON
echo json_encode($response);
}
thanks in advance, have a nice day
Theres a problem right at the while(), you're fetching the 1st row, and is correct.
Then, inside it you fetch the 2nd, which is what you intend, but when the iteration is repeating, the while will fetch the 3rd, and the inner the 4th, so you lost there the comparisson between 2nd and 3rd.
// fetch data from DB
$results = "...";
if (mysql_num_rows($result) < 1)
{
// no products found tell your users
return;
}
// lets make some variables to walk through the list
$previous = mysql_fetch_array($results);
$actual = null;
// and now lets walk through the list
while($actual = mysql_fetch_array($results))
{
// execute your logic here
// than at the end move the actual row to become the previous
$previous = $actual;
}
NOTICE you shouldn't use mysql_ * methods they're are deprecated. you can use the brother mysqli_ * or PDO
I would do something like this? But there is almost certainly a less resource intensive way to do it.
$x = 0;
$y = 1;
$total = mysql_num_rows(mysql_query("SELECT * FROM `the_place`");
while ($x < $total AND $y < total){
$query1 = "SELECT * FROM `the_place` LIMIT $x,1";
$query2 = "SELECT * FROM `the_place` LIMIT $y,1";
$row1 = mysql_fetch_array(mysql_query($query1);
$row2 = mysql_fetch_array(mysql_query($query2);
// Do comparison here
if ($row1 == $row2){
// etc
}
$x = $x++;
$y = $y++;
}
I don't understand why my code isn't working. The connection works and everything else however when I try to generate a unique random number and check from the MySQL if the number is there it still prints out a random number but it's not UNIQUE. Could anyone help me thx?
Here's my code:
$num = rand(1,5);
$sel_query = "SELECT * FROM test";
$result2 = $con->query($sel_query);
$i = 1;
for (;$i<2; $i++)
{
while($row = mysqli_fetch_array($result2))
{
if ($row['id'] == $num)
{
$num = rand(1,5);
$i = 0;
}
}
}
This should work:
$is_unique = false;
$num = false;
while (!$is_unique){
$num = rand(1,5);
$sel_query = "SELECT id from test where id = " . $num;
$result2 = $con->query($sel_query) or die($conn->error);
if (!mysqli_fetch_array($result2)){
$is_unique = true;
}
}
echo "Unique number is " . $num;
But if there aren't any more possible unique numbers, it will loop forever.
I know this is a bit old, but I found this question after needing a similar answer. I've taken Jodes's answer and updated it slightly, so that it won't run forever, is a function that returns the number, and accepts a mysqli connection as $mysqli:
function getUniqueNumber($mysqli)
{
$is_unique = false;
$num = false;
$times_run = 0;
while (!$is_unique)
{
if($times_run > 10)
{
echo "Run too many times, dying.";
die();
}
$num = rand(1,5);
$sel_query = "SELECT id from test where id = " . $num;
$result2 = $mysqli->query($sel_query) or die($mysqli->error);
if (!mysqli_fetch_array($result2))
{
$is_unique = true;
}
$times_run++;
}
return $num;
}
I need the script to output both rows. However, I can only get it to output the first one. Help please!
Here is my code:
<?php
$server = ""; // assume server name
$connect = mysqli_connect($server,,,) //assume password etc.
or die ("Couldn't connect to server"); //connect to admin database
$query = "SELECT mt FROM Content";
$result = mysqli_query($connect, $query)
or die ('Could not execute query.');
$nrows = mysqli_num_rows($result);
$row = mysqli_fetch_array($result);
$i = 0;
while ($i <= 30)
{
echo $row[$i];
$i++;
}
?>
You need to fetch into a row in a loop:
while ($row = mysqli_fetch_array($result)) { ...
Try to type:
while( $row = mysqli_fetch_array($result) )
{
echo $row[$i];
$i++;
}
You only fetch the first row.
You should do a while loop on your mysqli_fetch_array() to get both rows.
while ($row = mysqli_fetch_array($result)) {
for ($i = 0; $i < 30; $i++) {
echo $row[$i];
}
}
That should do it (like some of the other posted while I was writing but they forgot parts of the answer :-)
But I think that you should use the OO way of using mysqli.
You could use mysqli_fetch_all() to fetch all of the records.