MySQL query within another query's while loop in PHP - php

I have the following code:
$query = mysql_query("SELECT * FROM activity ORDER BY activity_time DESC LIMIT 50");
while($result = mysql_fetch_array($query)) {
extract($result);
if ($activity_type == "discussion") {
$query = mysql_query("SELECT * FROM discussions WHERE discussion_uuid = '$activity_ref'");
while($result = mysql_fetch_array($query)) {
extract($result);
echo $discussion_user . " said:<br>" . $discussion_text . "<br>";
}
} elseif ($activity_type == "file") {
}
}
But it just returns the last row. My goal is to have a chronological list of "activities" each displayed slightly differently depending on their type.

Your using $query and $result twice so the second loop is overwriting the result of the first and stopping...
$query = mysql_query("SELECT * FROM activity ORDER BY activity_time DESC LIMIT 50");
and
$query = mysql_query("SELECT * FROM discussions WHERE discussion_uuid = '$activity_ref'");
same with $results var...
I would suggest you change to $query and $query2 but best to use something like
$activies = mysql_query("SELECT * FROM activity ORDER BY activity_time DESC LIMIT 50");
while($activity = mysql_fetch_array($activies)) {
and
$discussions = mysql_query("SELECT * FROM discussions WHERE discussion_uuid = '$activity_ref'");
while($discussion = mysql_fetch_array($discussions)) {
I would also avoid using extract - as you might be overwriting vars your not expecting to...

You have to create another connection to the database so that you can run them at the same time.
OR
You can load the results of the first one into an array, and then just loop through the array.

Related

Why my script work half?

I’m using this code:
$date = date('Y-m-d');
$selStat = "SELECT obqva_id, COUNT(*) as broqch FROM statist WHERE date='$date' GROUP BY obqva_id ORDER BY COUNT(*) DESC LIMIT 8 ";
$queryStat = mysqli_query($conn, $selStat);
while ($rowStat = mysqli_fetch_array($queryStat)) {
$count = $rowStat['broqch'];
$id = $rowStat['obqva_id'];
echo $id.' - '.$count.'<br>';
$selBest = "SELECT * FROM view WHERE id='$id' GROUP BY $count ";
$queryBest = mysqli_query($conn, $selBest);
**$rowView = mysqli_fetch_array($queryBest);** this problem !
$selImage = "SELECT * FROM upload WHERE obqva_id='$id'";
$queryImage = mysqli_query($conn, $selImage);
$rowImage = mysqli_fetch_array($queryImage);
?>
Which produces this output:
First and next result has a problem, three and next have no problem... why?
First number 41 is ID next number total view.
it seems that the query is not valid, or there was no result.
thats why you get a bool instead of a resource.
you can filter that by putting your mysqli_query function in an IF statement, like this:
$selBest = "SELECT * FROM view WHERE id='$id' GROUP BY $count ";
if($queryBest = mysqli_query($conn, $selBest)){
$rowView = mysqli_fetch_array($queryBest);
}
else{
$rowView = false;
}
That's that, now for the query. You are trying to group the result on a number:
SELECT * FROM view WHERE id='$id' GROUP BY $count
Not sure why you want to group, as it seems that you only want to get some info on a specific id. In that case, i would get rid of the GROUP BY statement.

Add to string variable (string is a query)

i have a simple query who select me 3 news from table, but i wont to change this number from other file whith variable.
So this is query:
$query = 'SELECT * FROM news ORDER BY created_at DESC LIMIT 3';
I tried differently, but did not work...
Help please
My code(i can't answer on my question so i add it here)
$newsAmount = 3;
function get_news() {
$query = "SELECT * FROM news ORDER BY created_at DESC LIMIT $newsAmount";
$result = mysql_query($query);
$news = array();
while ($row = mysql_fetch_array($result)) {
$news[] = $row;
}
return $news;
if (!$result) {
trigger_error('Invalid query: ' . mysql_error() . " in " . $query);
}
}
This is this code.
Actually you can just do this:
$query = "SELECT * FROM news ORDER BY created_at DESC LIMIT $newsAmount";
But make sure to keep the string in double quotes so the variable can be evaluated, Single quotes will be printed out as it is.
Try to echo $query, you will notice that its being printed.
Try this:
$newsAmount = 3;
$query = 'SELECT * FROM news ORDER BY created_at DESC LIMIT ' + $newsAmount;
you cannot return an array like you did in your code.
I would suggest to do the query inside your main code instead of writing it in a function.

Echo the 2 last columns of tabel

I have a table and i want to echo the 2 last rows of my tabel, I used the below code but just the last one showed, what is the problem.
$result1 =(mysql_fetch_array(mysql_query("SELECT * FROM $table ORDER BY id DESC LIMIT 2")));
Print $result1['time'];
mysql_fetch_array = 1 fetch.
do it again for fetching 2nd result.
Also, use mysqli eh.
You're doing mysql_fetch_array only one time, so it gets the first element. If you want to get all the elements, then do it again, or use a loop.
Something like:
$query = "SELECT * FROM $table ORDER BY id DESC LIMIT 2";
while($row = mysql_fetch_array(mysql_query($query) )
{
echo $row['time'].'<br>';
}
For 2 Or more rows you need to loop it
$sql = mysql_query("SELECT * FROM $table ORDER BY id DESC LIMIT 2")
while($row=mysql_fetch_array($sql))
{
echo $row['time']."<br>";
}
$query = mysqli_query("SELECT * FROM $table ORDER BY id DESC LIMIT 2");
while ($result = mysqli_fetch_array($query)) {
echo $result['time'];
}
Gives out every return of your database (2 in this case). You should use mysqli_-functions.
Maybe you should try like this, since mysql_fetch_array returns only one row
while ($row = mysql_fetch_array($yourQuery)) {
echo $row["yourAlias"];
}
Further details here : http://fr2.php.net/manual/en/function.mysql-fetch-array.php
My solution:
$limit = 2;
$sql = "SELECT * FROM $table ORDER BY id DESC LIMIT $limit";
$result = mysql_query($sql);
$array = array(); $i = 0;
while($row = mysqli_fetch_array($result))
{
$array[$i] = $row;
$i++;
}
var_dump($array[0]);
var_dump($array[1]);

MySQL show results with inverted order?

I need to get the last 5 results, that's why I order them by Date DESC but I need to display the results from older to newer. How can I do this?
$data = mysql_query("SELECT * FROM Badges WHERE UID = '$user' ORDER by Date DESC LIMIT 5");
while($row = mysql_fetch_array( $data ))
{
print "<img class='badge' title='" . $row['Site'] . "' src='http://getfavicon.appspot.com/http://" . $row['Site'] . "?defaulticon=1pxgif' />";
}
$results = array();
while($row = mysql_fetch_array($data)) {
$results[] = $row;
}
$results = array_reverse($results);
foreach ($results as $row) {
echo $row['Site']; // etc
}
Manual link: http://php.net/function.array-reverse.php
$data = mysql_query("
SELECT * FROM (
SELECT * FROM Badges WHERE UID = '$user' ORDER by Date DESC LIMIT 5)
t ORDER BY Date
");
Also:
Please use mysql_real_escape_string (http://at2.php.net/manual/en/function.mysql-real-escape-string.php) for the variable $user. Depending on where you get that from it could be a security leak through sql injection.
You can actually order a second time in the same query.
I assume that you have an auto incrementad id (I'll call it 'EntryId' in this example) and then you hopefully should get what you need?
SELECT * FROM Badges WHERE UID = '$user' ORDER by Date DESC, EntryId ASC LIMIT 5

how can i controll while loop into another while loop

Suppose I have a while loop like:
$sql = mysql_query("SELECT * FROM tablename");
while($row = mysql_fetch_array($sql)){
$id = $row["id"];
$sql_2 = mysql_query("SELECT * FROM secondtable WHERE id != $id ");
while($ro = mysql_fetch_array($sql_2)){
$id2 = $ro["id2"];
echo $id2;
}
}
then if first query return 5 results i.e 1-5 and second query returns 3 results than if i want to echo out second query it gives me like this..........
111112222233333
than how can i fix to 123 so that the second while loop should execute according to number of times allowed by me........!! how can i do that.........!!
I'm not sure I 100% understand your question - it's a little unclear.
It's possible you could solve this in the query with a GROUP BY clause
$sql_2 = mysql_query("SELECT id FROM secondtable WHERE id != $id GROUP BY id");
But that would only work if you need just secondtable.id and not any of the other columns.
When you say "number of time allowed by me" do you mean some sort of arbitrary value? If so, then you need to use a different loop mechanism, such as Greg B's solution.
Do you want to explicitly limit the number of iterations of the inner loop?
Have you considered using a for loop?
$sql = mysql_query("SELECT * FROM tablename");
while($row = mysql_fetch_array($sql)){
$id = $row["id"];
$sql_2 = mysql_query("SELECT * FROM secondtable WHERE id != $id ");
for($i=0; $i<3; $i++){
$ro = mysql_fetch_array($sql_2);
$id2 = $ro["id2"];
echo $id2;
}
}
Your first while loop is iterating over all 5 results, one at a time.
Your second while loop is iterating over each of the 5 results, producing it's own set of results (i.e. 3 results for each of the 5 iterations, totaling 15 results).
I believe what you are trying to do is exclude all IDs found in your first loop from your second query. You could do that as follows:
$sql = mysql_query("SELECT * FROM tablename");
$exclude = array();
while($row = mysql_fetch_array($sql)) {
array_push($exclude, $row['id']);
}
// simplify query if no results found
$where = '';
if (!empty($exclude)) {
$where = sprintf(' WHERE id NOT IN (%s)', implode(',', $exclude));
}
$sql = sprintf('SELECT * FROM secondtable%s', $where);
while($row = mysql_fetch_array($sql_2)) {
$id2 = $row["id2"];
echo $id2;
}
$sql = mysql_query("SELECT * FROM tablename");
$tmp = array();
while($row = mysql_fetch_array($sql)){
$id = $row["id"];
if(!in_array($id, $tmp)) {
$sql_2 = mysql_query("SELECT * FROM secondtable WHERE id != $id ");
while($ro = mysql_fetch_array($sql_2)){
$id2 = $ro["id2"];
echo $id2;
}
$tmp[] = $id;
}
}
Saving all queried $id's in an array to check on the next iteration if it has already been queried. I also think that GROUPing the first query result would be a better way.
I agree with Leonardo Herrera that it's really not clear what you're trying to ask here. It would help if you could rewrite your question. It sounds a bit like you're trying to query one table and not include id's found in another table. You might try something like:
SELECT * FROM secondtable t2
WHERE NOT EXISTS (SELECT 1 FROM tablename t1 WHERE t1.id = t2.id);

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