Sentence of INSERT Mysqli Prepared, what's wrong with it?

Although you already know where the fault comes from, I'll leave you with a very functional example for the future, at least it will save you headaches, it is a method to find sometimes easier the small errors of confusion that one has easily with so much code. At least it will clarify where you should look for the failure in your sentence prepare() .

A possible example:

<?php
    //Sentencia preparada.
    $stmt = $conexion->prepare("INSERT INTO SANCIONES (cedula_sancionado, cedula_sancionador, cedula_superior, articulo_falta, aparte_falta, documento_seleccion, fecha_inicio, fecha_termino, dias_sancion, aclaratoria_sancion, estado_sancion_id, medida_id, articulo_circunstancia, agravante_seleccion, atenuante_seleccion, total_demerito, estado_id) VALUES (?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)");

    if (false===$stmt) { #Comprobación.
        exit('La sentencia preparada fallo: ' . htmlspecialchars($stmt->error));
    }

    //Ligamos parametros marcadores.
    $rc = $stmt->bind_param("iiiiisssisiiissdi",$cedula1,$cedula2,$cedula3,$articulo_falta,$aparte_falta,$documentos_implode,$fecha_inicio,$fecha_termino,$dias,$aclaratoria,$estado_sancion,$tipo_medida,$tipo_circunstancias,$agravantes_implode,$atenuantes_implode,$total_demerito,$estado);

    if (false===$rc) { #Comprobación.
        exit('la función bind_param() fallo: ' . htmlspecialchars($stmt->error));
    }

    //Ejecutamos sentencia.
    $rc = $stmt->execute();

    if (false===$rc) { #Comprobación.
        exit('la sentencia fallo al ejecutar: ' . htmlspecialchars($stmt->error));  
    } else {
        echo "Los datos se insertaron correctamente a la Base de datos :)";
    }
    $stmt->close(); //Cerramos sentencia.


?>

  

Fatal error: Call to a member function bind_param() on a non-object

As the error message says, $stmt seems not to be an object. Try debugging this using var_dump($stmt) , right after the ready call.

As you mentioned the prepared call fails and so it returns false - false is not an object, so you can not call bind_parm() on that.

Source SO

The main problem was that aggravating_selection was not receiving the value, and since it is not NULL this generated error.

The second $tipo_circunstancia was not the correct name, this was $tipo_circunstancias .

Therefore, I gave error as it was missing by adding the values of these variables to bind_param() .

I'm like this:

$stmt = $conexion->prepare("INSERT INTO SANCIONES (
      cedula_sancionado, 
      cedula_sancionador, 
      cedula_superior, 
      articulo_falta, 
      aparte_falta, 
      documento_seleccion, 
      fecha_inicio, 
      fecha_termino, 
      dias_sancion, 
      aclaratoria_sancion, 
      estado_sancion_id,
      medida_id,
      articulo_circunstancia,
      agravante_seleccion, 
      atenuante_seleccion, 
      total_demerito, 
      estado_id)) 
      VALUE (?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)");
$stmt->bind_param("iiiiisssisiiissdi"
 ,$cedula1
 ,$cedula2
 ,$cedula3
 ,$articulo_falta
 ,$aparte_falta
 ,$documentos_implode
 ,$fecha_inicio
 ,$fecha_termino
 ,$dias
 ,$aclaratoria
 ,$estado_sancion
 ,$tipo_medida
 ,$tipo_circunstancias
 ,$agravantes_implode
 ,$atenuantes_implode
 ,$total_demerito
 ,$estado);
$stmt->execute();
$stmt->close();
}