I'm trying to do a JOIN
(it's the first time) and I have this code but it shows me the following errors.
Warning: mysqli_query () expects at least 2 parameters, 1 given in C: \ xampp \ htdocs \ inventory \ int.php on line 5
Warning: mysqli_fetch_array () expects parameter 1 to be mysqli_result, null given in C: \ xampp \ htdocs \ inventory \ int.php on line 7
<?php
require("connect_db.php");
$query = "SELECT DISTINCT id_usuarios, nombre, ap, am, fecha, localidad, departamento FROM usuarios";
$res =mysqli_query($query);
$option = '';
while ($row = mysqli_fetch_array($res)){
$option.="option value=\"$row[id_usuarios]\">$row[nombre] </option>";
$option.="option value=\"$row[id_usuarios]\">$row[ap] </option>";
$option.="option value=\"$row[id_usuarios]\">$row[am] </option>";
$option.="option value=\"$row[id_usuarios]\">$row[fecha] </option>";
$option.="option value=\"$row[id_usuarios]\">$row[localidad] </option>";
$option.="option value=\"$row[id_usuarios]\">$row[departamento] </option>";
}
?>
<select>
<option value="-">Selecciona el usuario</option>
<?php echo $option; ?>
</select>
File connect_db.php
<?php
$mysqli = new MySQLi("", "","", "");
if ($mysqli -> connect_errno) {
die( "Fallo la conexión a MySQL: (" . $mysqli -> mysqli_connect_errno() . ") " . $mysqli -> mysqli_connect_error());
} else //echo "Conexión exitossa!";
// $link =mysqli_connect("localhost","","");
// if($link){
// mysqli_select_db($link,"academ");
// }
?>