javascript - How to make sure responseText does not return Oracle errors when something cannot be inserted into databse -

so i've got website, bunch of stuff sent through javascript php, if goes well, php returns response says "user created succesfully" if doesn't should return, "user not created" or "username exists", doesn't , instead throws bunch of oracle errors. there anyway make sure php doesn't send that, , sends 1 of 2 strings?

this javascript code:

window.onload = function findsubmitbutton() {     var button = document.queryselector(".send_info").addeventlistener("click", serverinteraction); /*unobtrusive javascript listener, added                                                                                                      create account button in html*/ }   function serverinteraction() {   var xmlhttp;   var inputarray;   var finalarray = [];   var jsonarray;   var userid;   if (window.xmlhttprequest){       xmlhttp = new xmlhttprequest();        /* used ie7+,firefox, opera, chrome, safari */   } else if (window.activexobject) {       xmlhttp = new activexobject("microsoft.xmlhttp");   /* compatibility ie6 browsers */   } else {       throw new error("your browser not compatible xmlhttp");       return false;   }    /* following section validates if required inputs have text in them , if password fields match*/   inputarray = document.queryselectorall("input[type=text]")   if (inputarray[1].value != inputarray[2].value){       alert("password doesn't match, please make sure password matches")       return false;   }    for(var = 0; < inputarray.length; i++){       if (inputarray[i].value == ""){           alert("please fill out of fields");           return false;       }         finalarray[i] = inputarray[i].value;   }     console.log(finalarray);     jsonarray = json.stringify({finalarray: finalarray});      console.log(jsonarray);      xmlhttp.onreadystatechange=function()       {           if (xmlhttp.readystate==4 && xmlhttp.status==200){             if (confirm(xmlhttp.responsetext)){                 window.location = 'index.html'             }             }       }      xmlhttp.open("post","php/senduserinfo.php", true);     xmlhttp.setrequestheader("content-type","application/json;charset=utf-8");     xmlhttp.send(jsonarray); } 

here's php, 1 causing problems:

<?php      $db_connection = oci_connect('user', 'password', 'localhost/database');  /*used establish connection between database , server*/                                                                                                              $finalarray = file_get_contents('php://input');                                   /*data retrieval*/                 $finalarray = json_decode($finalarray,true);                                      /*json decoding*/     $error;                       $username = $finalarray['finalarray'][0];              /* these variables data sent database */     $password = $finalarray['finalarray'][1];     $email = $finalarray['finalarray'][3];     $name = $finalarray['finalarray'][4];     $firstlastname = $finalarray['finalarray'][5];     $secondlastname = $finalarray['finalarray'][6];      $sqlvariableusuariotable = 'call usuario_package.add_usuario(:username, :password)';  /* sql statement send */     $sqlvariablepersontable = 'call person_package.add_person(:name, :first_ln, :second_ln, :username_person)';     $sqlvariableemailtable = 'call email_package.add_email(:email)';     $datatoinsertusuario = oci_parse($db_connection, $sqlvariableusuariotable);                         /* prepares statements sent database */     $datatoinsertperson = oci_parse($db_connection, $sqlvariablepersontable);     $datatoinsertemail= oci_parse($db_connection, $sqlvariableemailtable);       if(!$db_connection){                                    /* checks if connection database works */         exit ("server not connect database");     }      oci_bind_by_name($datatoinsertusuario, ':username', $username);                    /* binds variables string names */     oci_bind_by_name($datatoinsertusuario, ':password', $password);     oci_bind_by_name($datatoinsertemail, ':email', $email);     oci_bind_by_name($datatoinsertperson, ':name', $name);     oci_bind_by_name($datatoinsertperson, ':first_ln', $firstlastname);     oci_bind_by_name($datatoinsertperson, ':second_ln', $secondlastname);     oci_bind_by_name($datatoinsertperson, ':username_person', $username);       $arrayofdatatosend[0] = $datatoinsertusuario;     $arrayofdatatosend[1] = $datatoinsertemail;     $arrayofdatatosend[2] = $datatoinsertperson;      foreach ($arrayofdatatosend $value){         oci_execute($value);         if(oci_error($value)['code'] == 00001){             oci_rollback($db_connection);             exit ("the username or email have entered exists");         } else if (oci_error() != false){             oci_rollback($db_connection);             exit ("an error has occured database");         }      }     exit ("account succesfully created");     oci_close($db_connection);  ?> 

i know possible filter, or check user doesn't exist before inserting data, either way i'm sure there's simpler solution. i'd appreciate if me out that. i'm new @ this.

you need use try/catch block around code in php

foreach ($arrayofdatatosend $value){     try {         oci_execute($value);         exit ("account created");     } catch {         exit ("an error has occured database");         } } 

http://php.net/manual/en/language.exceptions.php