I have a question about PHP WHILE loops. I know that you can perform the action mysql_num_rows to get the number of results from a SELECT query.
But say I have 3 results come through the select query and i put them through a while loop, how do I assign a variable to the number each result is in the mysql_num_row.
Such as
1 for result 1
2 for result 2
3 for result 3.
Sorry if this is a bit confusing, but i can't seem to find an easy way to explain it.
Thanks
You do it like this:
$results = array();
While ($row = mysql_fetch_assoc($result))
{
$results[] = $row;
}
$myArray = array();
while($row = mysql_fetch_assoc($result)) {
$myArray[] = $row
}
$res=array();
$i=0;
While(mysql_fetch_array(...)){
$i++;
$res[$i]=value
//do logic
}
There are a few 'new' methods for pulling back data from MySQL now, if you're just starting out this might be the ideal time to have a look at them. This looks like a good place to start: http://www.php.net/manual/en/mysqlinfo.api.choosing.php.
Related
I'm fairly new to php, and I don't know how to work with arrays very well. Here's the deal, I want to add into a multidimensional array three or more values I obtain from my database, then I want to sort them based on the timestamp (one of the values). After that, I want to show all of the sorted values. I can't seem to do this, here's the code
$queryWaitingPatients = 'SELECT ArrivalTime, TargetTime, Order, Classification FROM exams WHERE (CurrentState = "Pending")';
$results = mysql_query($queryWaitingPatients) or die(mysql_error());
if (mysql_num_rows($results) == 0) {
echo '<p>There\'s currently no patient on the waiting list.</p>';
return;
}
while ($rows = mysql_fetch_array($results)) {
extract($rows);
//now is the part that I don't know, putting the values into an array
}
// I'm also not sure how to sort this according to my $TargetTime
asort($sortedTimes);
//the other part I don't know, showing the values,
Thanks for the help!
Well, let's look at your code. First, you have a query that's returning a result set. I don't recommend using mysql_fetch_array because it's not only deprecated (use mysqli functions instead) but it tends to lend itself to bad code. It's hard to figure out what you're referencing when all your keys are numbers. So I recommend mysqli_fetch_assoc (be sure you're fully switched to the mysqli functions first, like mysql_connect and mysqli_query)
Second, I really dislike using extract. We need to work with the array directly. Here's how we do this
$myarray = array();
while ($rows = mysqlI_fetch_assoc($results)) {
$myarray[] = $rows;
}
echo $myarray[0]['ArrivalTime'];
So let's go over this. First, we're building an array of arrays. So we initialize our overall array. Then we want to push the rows onto this array. That's what $myarray[] does. Finally, the array we're pushing is associative, meaning all the keys of the row match up with the field names of your query.
Now, the sorting really needs to be done in your query. So let's tweak your query
$queryWaitingPatients = 'SELECT ArrivalTime, TargetTime, `Order`, Classification
FROM exams
WHERE CurrentState = "Pending"
ORDER BY TargetTime';
This way, when your PHP runs, your database now churns them out in the correct order for your array. No sorting code needed.
$arr = array();
while ($rows = mysql_fetch_array($results)) {
array_push ($arr, $row);
}
print_r($arr);
<?php
$queryWaitingPatients = ' SELECT ArrivalTime, TargetTime, Order, Classification, CurrentState
FROM exams
WHERE CurrentState = "Pending"
ORDER BY TargetTime ';
$results = mysql_query($queryWaitingPatients) or die(mysql_error());
if ($results -> num_rows < 1)
{
echo '<p>There\'s currently no patient on the waiting list.</p>';
}
else
{
while ($rows = mysqli_fetch_array($results))
{
$arrivaltime = $row['ArrivalTime'];
$targettime = $row['targettime'];
$order = $row['Order'];
$classification = $row['Classification'];
echo "Arrival: ".$arrivaltime."--Target time: ".$targettime."--Order: ".$order."--Classification: ".$classification;
}
}
echo "Done!";
//or you could put it in a json array and pass it to client side.
?>
I'm trying to figure out the best way to do something like this. Basically what I want to do (in a simple example) would be query the database and return the 3 rows, however if there aren't 3 rows, say there are 0, 1, or 2, then I want to put other data in place of the missing rows.
Say my query returns 2 rows. Then there should be 1 list element returned with other data.
Something like this:
http://i42.tinypic.com/30xhi1f.png
$query = mysql_query("SELECT * FROM posts LIMIT 3");
while($row = mysql_fetch_array($query))
{
print "<li>".$row['post']."</li>";
}
//(this is just to give an idea of what i would likkeee to be able to do
else
{
print "<li>Add something here</li>";
}
You can get the number of items in the resultset with mysql_num_rows. Just build the difference to find out how many items are "missing".
There are three ways I can think of, get the row count with mysql_num_rows, prime an array with three values and replace them as you loop the result set, or count down from three as your work, and finish the count with a second loop, like this:
$result = db_query($query);
$addRows = 3;
while ($row = mysql_fetch_assoc($result){
$addRows--;
// do your stuff
}
while ($addRows-- > 0) {
// do your replacement stuff
}
If you dont find a row, Add extra information accordingly.
$query = mysql_query("SELECT * FROM posts");
for($i=0;$i<3;$i++){
$row = mysql_fetch_array($query);
if($row){
print "<li>".$row['post']."</li>";
}
//(this is just to give an idea of what i would likkeee to be able to do
else{
print "<li>Add something here</li>";
}
}
Assuming you store the rows in an array or somesuch, you can simply do some padding with a while loop (depending how you generate the other data):
while (count($resultList) < 3) {
// add another row
}
i have a query that should return 40 results:
$test = mysql_query(" SELECT fname FROM online_all WHERE verify_status = 'v' LIMIT 40 ");
if (!$test ) {print " - Mysql Error - ";echo fns_et_mysql_error(mysql_error());}
if i echo mysql_num_rows($test); i get 40. which means that i get the results
but when i print_r $roww = mysql_fetch_array($test); i get only one result.
there are no php errors.
You have to loop through the results with:
while($row = mysql_fetch_array($test)) {
// awesomeness with $row
}
Try using a loop.
while($row = mysql_fetch_array($test)){
}
mysql_fetch_array returns one row at a time. If you want to loop through all of them you do the following:
while ($row = mysql_fetch_array($test))
//Do something
http://php.net/manual/en/function.mysql-fetch-array.php
Check the documentation. mysql_fetch_array only fetches one row of data at a time. To get the data for all 40 rows you need a loop (like a for loop conditioned by mysql_num_rows).
You need to iterate the results from the query.
while($row = mysql_fetch_array($test))
{
// This is how you print fname.
echo $row[0];
}
Please refer to the documentation where there's also many useful tips of how you can use this function.
http://php.net/manual/en/function.mysql-fetch-array.php
You should also know that there exist another useful function for fetching results from mysql queries that fetches results as an associative array.
http://php.net/manual/en/function.mysql-fetch-assoc.php
You have to loop thru the rows:
while($row = mysql_fetch_array($test)){
var_dump($row);
//etectera
}
I currently have a database like the picture below.
Where there is a query that selects the rows with number1 equaling 1. When using
mysql_fetch_assoc()
in php I am only given the first is there any way to get the second? Like through a dimesional array like
array['number2'][2]
or something similar
Use repeated calls to mysql_fetch_assoc. It's documented right in the PHP manual.
http://php.net/manual/function.mysql-fetch-assoc.php
// While a row of data exists, put that row in $row as an associative array
// Note: If you're expecting just one row, no need to use a loop
// Note: If you put extract($row); inside the following loop, you'll
// then create $userid, $fullname, and $userstatus
while ($row = mysql_fetch_assoc($result)) {
echo $row["userid"];
echo $row["fullname"];
echo $row["userstatus"];
}
If you need to, you can use this to build up a multidimensional array for consumption in other parts of your script.
$Query="select SubCode,SubLongName from subjects where sem=1";
$Subject=mysqli_query($con,$Query);
$i=-1;
while($row = mysqli_fetch_array($Subject))
{
$i++;
$SubjectCode[$i]['SubCode']=$row['SubCode'];
$SubjectCode[$i]['SubLongName']=$row['SubLongName'];
}
Here the while loop will fetch each row.All the columns of the row will be stored in $row variable(array),but when the next iteration happens it will be lost.So we copy the contents of array $row into a multidimensional array called $SubjectCode.contents of each row will be stored in first index of that array.This can be later reused in our script.
(I 'am new to PHP,so if anybody came across this who knows a better way please mention it along with a comment with my name so that I can learn new.)
This is another easy way
$sql_shakil ="SELECT app_id, doctor_id FROM patients WHERE doctor_id = 201 ORDER BY ABS(app_id) ASC";
if ($result = $con->query($sql_shakil)) {
while ($row = $result->fetch_assoc()) {
printf ("%s (%s)\n", $row["app_id"], $row["doctor_id"]);
}
Demo Link
It looks like the complete solution has not been suggested yet
$Query="select SubCode,SubLongName from subjects where sem=1";
$Subject=mysqli_query($con,$Query);
$Rows = array ();
while($row = mysqli_fetch_array($Subject))
{
$Rows [] = $row;
}
The $Rows [] = $row appends the row to the array. The result is a multidimensional array of all rows.
I need to have a single row of data "printed out" through php.
So, take this example from w3schools:
http://www.w3schools.com/PHP/php_mysql_select.asp
There is a cicle that goes through all the rows ( in this case, 2) and prints them out. The end result is:
Peter Griffin
Glenn Quagmire
What I want is to be able to select row 1 or 2 (or more) and just have that row of data selected. Then I could say something like (I know this doesent work, just an example):
echo $row["Name",2];
And get:
Glenn Quagmire
I believe I have to get a special parameter in mysql_fetch_array, but I cant find it anywhere, and I bet its something really simple. Please help me out, full examples/tutorials/guides links are preferred.
you have 2 options. First is edit your SQL query like exmaple below this will return just 2nd row from database.
$result = mysql_query("SELECT * FROM Persons" WHERE id = 2);
Or during the foreach loop fetch all result into another array.
$result = mysql_query("SELECT * FROM Persons");
$rows = array();
while($row = mysql_fetch_array($result))
{
$rows[] = $row['FirstName'] . " " . $row['LastName'];
}
As far as i know mysql doesnt have a function to return the entire query as an array.
So you can switch to using PDO (recommended):
$sth = $dbh->prepare("SELECT name, colour FROM fruit");
$sth->execute();
$result = $sth->fetchAll();
echo $result[1]['name'];
or if you must use the mysql_functions just create an array with the loop:
while($row = mysql_fetch_array($result)) {
$result[] = $row;
}
echo $result[1]['name'];
fetchall the results into an array and print the row you want.