How to use array values in Where Clause in MySQL?

Sayuj Raghavan

10y1.5kPHP

Hi , this is the code which i am working on,

                         public function Welcome_Students($uid)
                  {

                    $q=mysqli_query($this->db,"SELECT School_Name FROM school_teacher_reg WHERE csr='$uid'")or die(mysqli_error($this->db));
               while($row1=mysqli_fetch_array($q,MYSQLI_ASSOC))
            {
                 $Schoolname=$row1[School_Name];
                }
                 $q1=mysqli_query($this->db,"SELECT csr FROM school_student WHERE               sch_name='$Schoolname'")or die(mysqli_error($this->db));

            while($row3=mysqli_fetch_array($q1,MYSQLI_ASSOC))
               {
                      $csr[]= $row3;     //till here i am getting the output
                      foreach($csr as $key){
                      $query=mysqli_query($this->db,"SELECT U.username,U.uid,U.bio FROM users U WHERE U.status='1' AND U.uid='$key' ORDER BY RAND() LIMIT 10")or die(mysqli_error($this->db));
                  while($row=mysqli_fetch_array($query,MYSQLI_ASSOC))
                   {
                     $data[]=$row;
                      }
                   }
                return data;
          } }
?>

I have been successfull executing till $csr[]= $row3; where i am able to fetch $csr[] array values .But when i try to fetch each values of that array in $csr[], I am unable to retrieve values from the table using the following query inside the foreach loop

"SELECT U.username,U.uid,U.bio FROM users U WHERE U.status='1' AND U.uid='$key' ORDER BY RAND() LIMIT 10").

12 Replies

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Sayuj Raghavan10y ago
that is there , i just copied the snippet where the functioning of code happens
Guest User10y ago
$updatesarray=$Wall->Welcome_Students($uid);

print_r($updatesarray);
?>
That cannot be all there is. There should at least be code to instantiate the $Wall, something like this:

$Wall = new YourClassNameHere();
Sayuj Raghavan10y ago
public function Welcome_Students($uid)
{

$q=mysqli_query($this->db,"SELECT School_Name FROM school_teacher_reg WHERE csr='$uid'")or die(mysqli_error($this->db));

while($row1=mysqli_fetch_array($q,MYSQLI_ASSOC))
{
$Schoolname=$row1[School_Name];
}
$q1=mysqli_query($this->db,"SELECT csr FROM school_student WHERE sch_name='$Schoolname'")or die(mysqli_error($this->db)); while($row3=mysqli_fetch_array($q1,MYSQLI_ASSOC)) {
$csr[]= $row3;
foreach($row3 as $key)
{
$query=mysqli_query($this->db,"SELECT U.username,U.uid,U.bio FROM users U WHERE U.status='1' AND U.uid='$key['csr']' ORDER BY RAND() LIMIT 10")or die(mysqli_error($this->db));

while($row=mysqli_fetch_array($query,MYSQLI_ASSOC))
{ $data[]=$row;
}} } return $data; }
The code where this function uses...

$updatesarray=$Wall->Welcome_Students($uid);

print_r($updatesarray);
?>
This page itself is not loading .
Guest User10y ago
What have you tried exactly, and what didn't work? Did you get error messages? Please be more specific.
Sayuj Raghavan10y ago
Are you sure it will work ? I tried it , but didn't work .Is their any other alternative ?
Guest User10y ago
Either use $key[0] in your query or use $key['csr']
Sayuj Raghavan10y ago
Array ( [0] => Array ( [csr] => 40 ) [1] => Array ( [csr] => 41 ) [2] => Array ( [csr] => 42 ) [3] => Array ( [csr] => 43 ) [4] => Array ( [csr] => 44 ) [5] => Array ( [csr] => 44 ) [6] => Array ( [csr] => 44 ) )
Guest User10y ago
Do:

print_r($csr);

and copy the output here.
Sayuj Raghavan10y ago
It contains a set of user_ids { 40,41,44,45,43} namely.
Guest User10y ago
Not sure, exactly what value in that array do you need to use. Show a dump perhaps of what it contains.
Sayuj Raghavan10y ago
How to get array values to check inside that query one by one,since $csr[] contains a set of values ?
Guest User10y ago
Your code:

   $csr[]= $row3;

$row3 is an array, which you assign to another array. The following code:

   foreach ($csr as $key) {

means that $key is actually an array, and therefor not a value that you can use in your query. If you output your generated query I assume you'll something like this:

    SELECT U.username,U.uid,U.bio FROM users U WHERE U.status='1' AND U.uid='Array ()' ORDER BY RAND() LIMIT 10

Which will not return any results.