php - Codeigniter logic of PC/tl/sc/pm email -

i have array

array (    [0] => array        (         [pm] => 14         [ld] => 578         [tl] => 56         [sc] => 67         [pc] =>         ) ) 

the above ids of pc/pm/tl/ld. use them in database query email ids.

i want use following logic, email template should work pc in “to” , rest cc’ed.

• if no pc assigned, tl in email rest in cc
• if no tl, ld in email rest in cc
• if no ld, pm in email rest in cc
• if no pm, sc in email rest in cc

also want add email ids array. if start with:

array (      [pc] =>      [tl] => 1109      [ld] => 838      [pm] => 715,824,694      [sc] => 727 )  

i perform sql ($user_sql):

select id,email   new_login   id in (1109,838,715,824,694,727)  ,    status = 1 

to output:

array (      [694] => a@exateam.com      [715] => b@gmail.com      [727] => c@gmail.com      [824] => d@gmail.com      [838] => e@gmail.com      [1109] => m@gmail.com  ) 

this code below will:

• order given ids according priority of two-letter codes;
• create 1 list of ids splitting multi-id strings separate array elements;
• query database receive corresponding emails addresses
• store these email addresses in key/value pairs (id/email) in right array variable ($to or $cc)

you did not specify database engine use. code assumes use mysqli , have conection object named $con. database part of code untested. should @ least give idea how proceed.

comments in code should clarify happening:

// example data: $data = array (    array ("pm" => "715,824,694", "ld" => "838", "tl" => "1109",            "sc" => "727", "pc" => null) );  // define priority order of different 2 letter codes: $order = array_flip(array("pc", "tl", "ld", "pm", "sc"));  // iterate on data foreach ($data $row) {     // order $row elements priority , filter out empty values:     $row = array_filter(array_merge($order, $row));     // if nothing left over, skip row     if (count($row) == 0) continue;     // count number of ids in "to" addressee:     $to_count = count(explode(',', array_values($row)[0]));     // create 1 list of ids , turn comma-separated items      // separate array elements:     $row = explode(',', implode(',', $row));     // initialise arrays receive email addresses / cc     $to = array();     $cc = array();     // retrieve email addresses database.     // need valid mysqli connection object: $con     // prepare sql statement avoid sql injection, , produce     // right number of question marks in it:     $query = "select id,email new_login status = 1               , id in (" . implode(',', array_fill(0, count($row), '?')) . ") ";     $stmt = $con->prepare($query) or die($con->error());     // bind id values prepared sql statement     call_user_func_array(array($stmt, 'bind_param'), $row);     // execute sql query     $stmt->execute();     // fetch result array     $res = $stmt->get_result();     while($email = $res->fetch_array(mysqli_assoc)) {         // check whether concerns or cc address:         if (array_search($email["id"], $row) < $to_count) {             $to[$email["id"]] = $email["email"];         } else {             $cc[$email["id"]] = $email["email"];         }     }     $stmt->close();     // use $to , $cc send email     // ... }