How to validate if certain value is duplicate or if certain input field is not filled using PHP AJAX-CodePudding

This is a simple REST API for listing, creating and deleting products in/from database. I am having issues with validating/checking if certain values duplicate or if certain input field is not filled. I've attempted doing that with rowCount for the duplicate, in the php file, however I think there must be a better way for this, however I am having issues finding out how to do that.

here is the post.php

$query_check = 'SELECT * FROM skandi WHERE sku = :sku'; 
$stmt_check = $this->conn->prepare($query_check);
$stmt_check->bindParam(':sku', $this->sku);
$stmt_check->execute();

if ($stmt_check->rowCount() > 0) {
    echo 'product name already exists!';
} else {
$query = 'INSERT INTO ' . $this->table . '
        SET             
        
        sku = :sku,
        name = :name,
        price = :price,
        productType = :productType,
        size = :size,
        weight = :weight,
        height = :height,
        length = :length,
        width = :width';

        $stmt = $this->conn->prepare($query);
      
        $this->sku;
        $this->name; 
        $this->price; 
        $this->productType; 
        $this->size;
        $this->weight;
        $this->height;
        $this->length;
        $this->width;

        $stmt->bindParam(':sku', $this->sku);
        $stmt->bindParam(':name', $this->name);
        $stmt->bindParam(':price', $this->price);
        $stmt->bindParam(':productType', $this->productType);
        $stmt->bindParam(':size', $this->size);
        $stmt->bindParam(':weight', $this->weight);
        $stmt->bindParam(':height', $this->height);
        $stmt->bindParam(':length', $this->length);
        $stmt->bindParam(':width', $this->width);

        if($stmt->execute()) {
            return true;

        } else {
            ini_set('display_errors',1);

            return false;
        }

    }

this is the ajaxcall for posting

$(document).ready(function () {
$("#saveBtn").click(function (e) {
e.preventDefault();

//serialize form data
var url = $("form").serialize();

//function to turn url to an object
function getUrlVars(url) {
  var hash;
  var myJson = {};
  var hashes = url.slice(url.indexOf("?")   1).split("&");
  for (var i = 0; i < hashes.length; i  ) {
    hash = hashes[i].split("=");
    myJson[hash[0]] = hash[1];
  }
  return JSON.stringify(myJson);
}
     
//pass serialized data to function
var test = getUrlVars(url);

//post with ajax
$.ajax({
  type: "POST",
  url: "/api/post/create.php",
  data: test,
  ContentType: "application/json",

  success: function () {
    alert("successfully posted");
  },
  error: function () {
    
    console.log("Could not be posted");
  },
});

}); });

CodePudding user response：

You should not be checking for duplicates. Set a unique constraint on the relevant column and then attempt the insert. Catch the duplicate error if any and handle however you want.

CodePudding user response：

You can check if certain input fields are not filled using the isset() function in PHP: For example:

   if (isset($_POST['sku']) {
      //exists
   }

While to check if the product already exists you have to check if it exists in database so you must necessarily make a query.