How to use array values in Where Clause in MySQL?

Question

Hi  this is the code which i am working on public function Welcome_Students($uid) { $q=mysqli_query($this->dbSELECT School_Name FROM school_teacher_reg WHERE csr='$uid')or die(mysqli_error($this->db)); while($row1=mysqli_fetch_array($qMYSQLI_ASSOC)) { $Schoolname=$row1[School_Name]; } $q1=mysqli_query($this->dbSELECT csr FROM school_student WHERE sch_name='$Schoolname')or die(mysqli_error($this->db)); while($row3=mysqli_fetch_array($q1MYSQLI_ASSOC)) { $csr[]= $row3; //till here i am getting the output foreach($csr as $key){ $query=mysqli_query($this->dbSELECT U.usernameU.uidU.bio FROM users U WHERE U.status='1' AND U.uid='$key' ORDER BY RAND() LIMIT 10)or die(mysqli_error($this->db)); while($row=mysqli_fetch_array($queryMYSQLI_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 $csr[] I am unable to retrieve values from the table using the following query inside the foreach loop SELECT U.usernameU.uidU.bio FROM users U WHERE U.status='1' AND U.uid='$key' ORDER BY RAND() LIMIT 10).

Sayuj Raghavan · Answer

that is there  i just copied the snippet where the functioning of code happens

pritaeas · Answer

$updatesarray=$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 Raghavan · Answer

public function Welcome_Students($uid) { $q=mysqli_query($this->dbSELECT School_Name FROM school_teacher_reg WHERE csr='$uid')or die(mysqli_error($this->db)); while($row1=mysqli_fetch_array($qMYSQLI_ASSOC)) { $Schoolname=$row1[School_Name]; } $q1=mysqli_query($this->dbSELECT csr FROM school_student WHERE sch_name='$Schoolname')or die(mysqli_error($this->db)); while($row3=mysqli_fetch_array($q1MYSQLI_ASSOC)) { $csr[]= $row3; foreach($row3 as $key) { $query=mysqli_query($this->dbSELECT U.usernameU.uidU.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($row=mysqli_fetch_array($queryMYSQLI_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 .

pritaeas · Answer

What have you tried exactly and what didn't work? Did you get error messages? Please be more specific.

Sayuj Raghavan · Answer

Are you sure it will work ? I tried it  but didn't work .Is their any other alternative ?

pritaeas · Answer

Either use $key[0] in your query or use $key['csr']

Sayuj Raghavan · Answer

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 ) )

pritaeas · Answer

Do: print_r($csr); and copy the output here.

Sayuj Raghavan · Answer

It contains a set of user_ids { 4041444543} namely.

pritaeas · Answer

Not sure exactly what value in that array do you need to use. Show a dump perhaps of what it contains.

Sayuj Raghavan · Answer

How to get array values to check inside that query one by onesince $csr[] contains a set of values ?

pritaeas · Answer

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.usernameU.uidU.bio FROM users U WHERE U.status='1' AND U.uid='Array ()' ORDER BY RAND() LIMIT 10 Which will not return any results.