Problem in including data through a form using PHP and Mysql

Question

<?php
define('HOST', 'localhost');
define('USUARIO', 'root');
define('SENHA', '');
define('DB', 'login');

$conexao = mysqli_connect(HOST, USUARIO, SENHA, DB) or die ('Nao foi possivel conectar');

I have a problem to make an entry in the database, whenever I try to send an error where the page is redirected but it is not done the actual insertion in the table,Besides, it is a reused code of the same project only made changes to the insertions and variables if it is useful I am using bootstrap 4 and Jquery 3.4.1

<?php
include("conexao.php");

$produto = mysqli_real_escape_string($conexao, trim($_POST['produto']));
$quantidadeLote = mysqli_real_escape_string($conexao, trim($_POST['quantidadeLote']));
$precoCompra = mysqli_real_escape_string($conexao, trim($_POST['precoCompra']));
$preceVenda = mysqli_real_escape_string($conexao, trim($_POST['preceVenda']));
$fornecedor = mysqli_real_escape_string($conexao, trim($_POST['fornecedor']));

$sql = "INSERT INTO produtos(produto, quantidadeLote, precoCompra, precoVenda, fornecedor) VALUES ('$produto',
'$quantidadeLote', '$precoCompra', '$preceVenda', 'fornecedor')";

$conexao->close();

header('Location: produtos.php');
exit;
?>

<?php
include ('menu.php');
?>
<link rel="stylesheet" type="text/css" href="./assets/css/painel.css">

<main role="main" class="col-md-9 ml-sm-auto col-lg-10 px-4">
	<div class="d-flex justify-content-between flex-wrap flex-md-nowrap align-items-center pt-3 pb-2 mb-3 border-bottom">
		<h1 class="h2">Cadastro de Produtos</h1>
	</div>
  <div id="container">

  	<form action="processaCP.php" action="POST">
  	  <div class="form-row">
  	      <div class="form-group col-md-6">
  	        <label for="Produto">Produto</label>
  	        <input type="text" class="form-control" name="produto" placeholder="Produto">
  	      </div>
  	      <div class="form-group col-md-3">
  	        <label for="Quantidade">Quantidade Lote</label>
  	        <input type="text" class="form-control" name="quantidadeLote" placeholder="100">
  	      </div>
  	    </div>
  	    <div class="form-row">
	  	    <div class="form-group col-md-3">
	  	    	<label for="ComraUnidade">Preço de Compra Unidade</label>
				    <input type="text" class="form-control" name="precoCompra" placeholder="R$0,00">
	  	    </div>
          <div class="form-group col-md-3">
    				<label for="VendaUnidade">Preço de Venda Unidade</label>
    				<input type="text" class="form-control" name="preceVenda" placeholder="R$0,00">
			</div>
			<div class="form-group col-md-6">
			  <label for="Fornecedor">Fornecedor</label>
			  <input type="text" class="form-control" name="fornecedor">
			</div>
		</div>
		<br>	
		<div class="input-group-prepend" style="display:inline-block; vertical-align: middle;">
      <button class="btn btn-outline-success" type="submit">Savar</button>
      &ensp;<!-- espaço -->
      <button class="btn btn-outline-secondary" type="reset">Cancelar</button>
    </div>
  	</form>
  	<br>
  	<div class="d-flex justify-content-between flex-wrap flex-md-nowrap align-items-center pt-3 pb-2 mb-3 border-bottom">
  		<h1 class="h3">Lista de Produtos</h1>
  	</div>
  </div>
    <span id="conteudoP"></span>
 </main>

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
 <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js"></script>
 <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js"></script>
 <script type="text/javascript" src="./assets/js/painel.js"></script>
 <script type="text/javascript" src="./assets/js/jquery-3.4.1.min.js"></script>
 <script type="text/javascript" src="./assets/js/jquery.mask.min.js"></script>
 <script>
     $(document).ready(function () {
       $.post('listarP.php', function(retorna){
         //Subtitui o valor no seletor id="conteudo"
         $("#conteudoP").html(retorna);
       });
     });
   </script>

Answer 1

This is Emerson, all right? I took a quick look at your code and noticed that when creating your SQL, you do not inform the last field as variable, you put "vendor" instead of "$vendor".

Another detail, I don’t know if PHP recognizes the variable of your text the way you put it, normally I put the variable inside keys {}

You put it like this:

$sql = "INSERT INTO produtos(produto, quantidadeLote, precoCompra, precoVenda, fornecedor) VALUES ('$produto',
'$quantidadeLote', '$precoCompra', '$preceVenda', 'fornecedor')";

That way you used I don’t remember working, I know it works like this:

$sql = "INSERT INTO produtos(produto, quantidadeLote, precoCompra, precoVenda, fornecedor) VALUES ('{$produto}', '{$quantidadeLote}', '{$precoCompra}', '{$preceVenda}', '{$fornecedor}')";

I hope I helped, a hug.

Answer 2

As you said the code was copied from another working service, your problem can only be with the BD user. Check the permissions designed (read, write, update, delete data, modify tables, etc) to register users in Mysql.

TIP: Abandon mysqli, migrate to PDO (PHP Data Object).