mysql - Check duplicate before inserting in database from CSV upload in PHP -

when uploading csv file check whether email , phone numbers inserted or not.

i facing problems if condition checks these inputs.

for mysqli_num_rows() function, not getting values , create problem csv problem.

<?php  if(isset($_post["import"])){     $filename=$_files["file"]["tmp_name"];     if($_files["file"]["size"] > 0)     {         $file = fopen($filename, "r");         while (($emapdata = fgetcsv($file, 10000, ",")) !== false)         {             $contractorid=$_session['id'];             $flag=false;              $sqlcheckemail = "select * user user_email='$emapdata[1]'";             $result_check_email = @mysqli_query($conn,$sqlcheckemail);             $row_check_email=mysqli_num_rows($result_check_email);             if($row_check_email>0){                 $flag=true;                 echo "this user email ".$emapdata[1]." has been added.";             }             if($flag!=true){                 //it wiil insert row our subject table our csv file`                 $sql = "insert user (`contractor_id`,`user_email`, `user_address`, `user_phone`, `user_name`,user_sex,user_age,user_birthday)                          values('$contractorid','$emapdata[1]','$emapdata[2]','$emapdata[3]','$emapdata[4]','$emapdata[5]','$emapdata[6]','$emapdata[7]')";                  //we using mysql_query function. returns resource on true else false on error                 $result = mysql_query( $sql, $conn );                 if(! $result )                 {                     echo "<script type=\"text/javascript\">                     alert(\"????????????csv?????????????????\");                     </script>";                 }             }           }          fclose($file);          if($flag!=true){              //throws message if data imported mysql database excel file              echo "<script type=\"text/javascript\">                         alert(\"csv???????????????\");                         window.location = \"index.php\"                     </script>";          }         //close of connection         mysql_close($conn);       } }     ?> 

i wouldn't solve on application level. let database job you. each record doing separate select statement result in horrible performance.

you seem check, if entry exists based on column email. have unique index on column. can do

load data infile 'file_name.csv' ignore /*with checks based on unique index on email, if record exists*/ table tbl_name /*adjust table name*/ fields terminated ',' /*adjust following csv file*/ optionally enclosed '"' (email_column, another_column) /*name columns of table*/ ; 

you can read more command here.