How to mount the HTML of a "select" via PHP, using data from DB

Question

I’m having trouble properly assembling a <select> within PHP, with data returned by mysqli.

I tried this way:

<?php
   $con = new mysqli("localhost", "root", "senha","bancodedados" ) or die (mysql_error());
   $query = $con->query("SELECT * FROM pv_tipo_info_questionario");
   while($reg = $query->fetch_array()) {
     echo "<select><option name=\"ativo\" value=";
     echo $reg["cod_tipo_info"];
     echo "\"\>";
     echo "<select><option name=\"ativo\" value=";
     echo $reg["tipo_info_questionario"];
     echo "\"\>";
   }
?>

Answer 1

The existing responses already address the problem effectively, I will leave my suggestion to contemplate the optimization of the script and more effectively monitor the outcome of the:

<?php
// iniciar a variável que vai conter o HTML
$outputHtml = '';

// preparar uma mensagem de erro para o utilizador
$erro = '<p>Sem resultados provenientes da Base de Dados!</p>';

// consultar a base de dados
$resultados = $con->query("SELECT * FROM pv_tipo_info_questionario");

// verificar se foram devolvidos resultados
if ($resultados && $resultados->num_rows === 0) { 
    $outputHtml = $erro;
}
else {

    $optionsHtml = '';

    // temos resultados, processar cada um
    while ($row = $results->fetch_array()) {

      // acrescentar à variável que contém o HTML os dados deste registo
      $optionsHtml.= '
      <option value="'.$row["cod_tipo_info"].'">
        '.$row["tipo_info_questionario"].'
      </option>';
    }

    // verificar se temos dados para completar a SELECT
    if (!empty($optionsHtml)) {
      $outputHtml = '
      <select name="ativo">
        '.$optionsHtml.'
      </select>';
    }
    else {
      $outputHtml = $erro;
    }
}

echo $outputHtml;
?>

This way not only are you preparing the checkbox according to the difficulty expressed in the question, but you are also ensuring that if something goes wrong, the user will not see an empty page or incomplete HTML leading to a break in the layout.

Answer 2

Your problem is quite simple Open, select should be a tag with the options inside this way:

<select name="exemplo">
 <option>Exemplo 1</option>
 <option>Exemplo 2</option>
 <option>Exemplo 3</option>
</select>

Your code is generating a select by loop in while, switch to:

echo "<select name=\"ativo\">";
while($reg = $query->fetch_array()) { echo "";

echo "<option value=";
echo $reg["tipo_info_questionario"];
echo "\"\> String de descricao</option>";
} `'
echo "</select>";

Since in addition to the value coming from value, each option must contain a String for its description (it may be the same).

See you around

Answer 3

That would be the right way to do the while to fill your select

$query = $con->query("SELECT * FROM pv_tipo_info_questionario");

echo "<select name='ativo'>";
while($reg = $query->fetch_array()) {
  echo "<option value='".$reg["cod_tipo_info"]."'>".$reg["tipo_info_questionario"]."</option>";
}
echo "</select>";

This code should present something similar to this

<select name='ativo'>
   <option value='1'>Exemplo</option>
   <option value='2'>Exemplo</option>
   <option value='3'>Exemplo</option>
</select>

Answer 4

An option, which I particularly like to use, separating as much as possible the PHP of HTML:

<?php
$con = new mysqli("localhost", "root", "senha","bancodedados" ) or die (mysql_error());
$query = $con->query("SELECT * FROM pv_tipo_info_questionario");
?>
<select name="ativo">
    <?php while($reg = $query->fetch_array()) { ?>
    <option value="<?=$reg["cod_tipo_info"]?>"> <?=$reg["tipo_info_questionario"]?> </option>
    <?php }?>
</select>

NOTE: Note what to do <?=$reg["cod_tipo_info"]?> is the same as <?php echo $reg["cod_tipo_info"];?>, for more information see short_open_tag. If you do not have the short tags option enabled on the server or prefer not to use, you can do:

<?php
$con = new mysqli("localhost", "root", "senha","bancodedados" ) or die (mysql_error());
$query = $con->query("SELECT * FROM pv_tipo_info_questionario");
?>
<select name="ativo">
    <?php while($reg = $query->fetch_array()) { ?>
    <option value="<?php echo $reg["cod_tipo_info"]?>"> <?php echo $reg["tipo_info_questionario"]?> </option>
    <?php }?>
</select>

Answer 5

Look Fabricio that’s the code to fill your select with data from a table returned via Mysql and PHP.

<select name="ativo">
 <option> <?php echo "--Seleciona o tipo_info_questionario---" ?></option>         
    <?php 
   //Chamar a tua conexao
    $result= mysql_query("select * from pv_tipo_info_questionario");
      echo "<pre>";
          while($lista = mysql_fetch_array($result)) {
          print_r($lista);
      echo "<option value='{$lista['cod_tipo_info']}'>{$lista['tipo_info_questionario']}</option>";

    }
    echo "</pre>";
    ?>
</select>

NOTE: You can save this code to the PHP extension and then call it in HTML. Example of the name: SelectAtivo.php

To Call in HTML would be as follows. Example Call:

<label>ATIVO:</label> <?php require_once 'SelectAtivo.php';?>

Answer 6

If you are using PHP class with Mysql this is how it works

    <label for="" id="Cidade">CIDADE:  </label>
    <select name="ComboboxCidade" size="1" id="ComboboxCidade">
         <?php  
        $cidades = CidadeDao::listaCidade();
        if($cidades <> null){   
            foreach ($cidades   as $key => $row) {
                echo "<option value=";
                echo $row ->getIdCidade();
                echo "\"\>";
                echo $row ->getNome();
                echo "</option>";
            }
        }
        ?>