¿Por qué $ wpdb-> show_errors () y print_error () muestran una salida incluso si la salida de la consulta es correcta?

Question

¿Por qué $ wpdb-> show_errors () y print_error () muestran una salida incluso si la salida de la consulta es correcta?

9

71761 2015-02-23

Para resolverel siguienteproblema,consulte https://wordpress.stackexchange.com/questions/178995/sanitize-a-working-query-string-by-using-wpdb-prepare-fails-with-mysql-db -er me encontré con un comportamientobastanteextraño. Incluso quemi consulta utilizadaera correcta ymostrabael resultado correcto.

 global $wpdb;
$wpdb->show_errors(); 
$pageposts = $wpdb->get_results( 
        $wpdb->prepare(
          "
          SELECT skposts.*
          FROM  $wpdb->posts skposts,
                $wpdb->postmeta skpostmeta1,
                $wpdb->postmeta skpostmeta2
          WHERE skposts.ID = skpostmeta1.post_id
            AND skposts.ID = skpostmeta2.post_id
            AND skpostmeta1.meta_key = %s
            AND skpostmeta2.meta_key = %s
            AND skposts.post_type = %s
            AND skposts.post_status = %s
          ORDER BY skpostmeta1.meta_value ASC,
                   skpostmeta2.meta_value ASC
          ", 
          'class_day',
          'class_start',
          'courses',
          'publish'
        )
, OBJECT
);
$wpdb->print_error();

No obstante,siempre quetenga show_errors y print_error activos,obtengo una salida deerror de labase de datos de WPjunto a:

 WordPress database error: []
SELECT skposts.* FROM hmjtZ_posts skposts, hmjtZ_postmeta skpostmeta1, hmjtZ_postmeta skpostmeta2 WHERE skposts.ID = skpostmeta1.post_id AND skposts.ID = skpostmeta2.post_id AND skpostmeta1.meta_key = 'class_day' AND skpostmeta2.meta_key = 'class_start' AND skposts.post_type = 'courses' AND skposts.post_status = 'publish' ORDER BY skpostmeta1.meta_value ASC, skpostmeta2.meta_value ASC

¿Peropor qué? Hubieraesperado que semostrara una salida solo si algo salemal,como unerror o una advertencia,pero deestamanera semuestra algotodoeltiempo.

In order of figuring out the following issue, see https://wordpress.stackexchange.com/questions/178995/sanitize-a-working-query-string-by-using-wpdb-prepare-fails-with-mysql-db-er i ran into an rather odd behaviour. Even that my used query was correct and showing the right output.

global $wpdb;
$wpdb->show_errors(); 
$pageposts = $wpdb->get_results( 
        $wpdb->prepare(
          "
          SELECT skposts.*
          FROM  $wpdb->posts skposts,
                $wpdb->postmeta skpostmeta1,
                $wpdb->postmeta skpostmeta2
          WHERE skposts.ID = skpostmeta1.post_id
            AND skposts.ID = skpostmeta2.post_id
            AND skpostmeta1.meta_key = %s
            AND skpostmeta2.meta_key = %s
            AND skposts.post_type = %s
            AND skposts.post_status = %s
          ORDER BY skpostmeta1.meta_value ASC,
                   skpostmeta2.meta_value ASC
          ", 
          'class_day',
          'class_start',
          'courses',
          'publish'
        )
, OBJECT
);
$wpdb->print_error();

Never the less as long as i have show_errors and print_error active i get an WP database error output alongside:

WordPress database error: []
SELECT skposts.* FROM hmjtZ_posts skposts, hmjtZ_postmeta skpostmeta1, hmjtZ_postmeta skpostmeta2 WHERE skposts.ID = skpostmeta1.post_id AND skposts.ID = skpostmeta2.post_id AND skpostmeta1.meta_key = 'class_day' AND skpostmeta2.meta_key = 'class_start' AND skposts.post_type = 'courses' AND skposts.post_status = 'publish' ORDER BY skpostmeta1.meta_value ASC, skpostmeta2.meta_value ASC

But why? I would have expected that an output is shown only if something goes wrong like an error or warning but this way something is shown all the time.

1 respuesta

votos

David Gard · Accepted Answer · 2015-02-23

20

2015-02-23

El resultado quepublicó anteriormenteesel comportamientoesperadopara $wpdb->print_error() si se cumple lo siguiente:

Ejecuta un único sitio,no varios sitios
$wpdb->suppress_errors seestableceen falso
$wpdb->show_errors seestableceen falso

Porel aspecto de su código,cumple contodasesas condiciones.

Tengaen cuentatambién que,amenos que los haya desactivado anteriormente,$wpdb->show_errors seestableceen true deformapredeterminada,por lo quenonecesita llamar $wpdb->show_errors().

Paragenerar algo solo cuando hay unerror debase de datos,puede hacer una deestas dos cosas:

1:muestraelerror y agregaelerror al registro

Además de apareceren lapantalla,elmétodo $wpdb->print_error() registrará suerror. Siestees un comportamiento deseable (recomendado),puede hacerlo:

 if($wpdb->last_error !== '') :
    $wpdb->print_error();
endif;

2:muestraelerrorperono lo registra

Sinoestáinteresadoen registrarelerror,puede agregar supropiafunción my_print_error() y usarlaen lugar de $wpdb->print_error() -

 function my_print_error(){

    global $wpdb;

    if($wpdb->last_error !== '') :

        $str   = htmlspecialchars( $wpdb->last_result, ENT_QUOTES );
        $query = htmlspecialchars( $wpdb->last_query, ENT_QUOTES );

        print "<div id='error'>
        <p class='wpdberror'><strong>WordPress database error:</strong> [$str]<br />
        <code>$query</code></p>
        </div>";

    endif;

}

Últimaedición:error de sintaxis

The output that you posted above is expected behaviour for $wpdb->print_error() if the following is true -

You are running a single site, not multisite
$wpdb->suppress_errors is set to false
$wpdb->show_errors is set to false

From the looks of your code, you meet all those conditions.

Note also that, unless you have turned them off previously, $wpdb->show_errors is set to true by default, so you don't need to call $wpdb->show_errors().

To output something only when there is a DB error you can do one of these two things -

1 - Output the error and add the error to the log

As well as outputting on the screen, the $wpdb->print_error() method will log your error. If this is desirable behaviour (recommended), you can do this -

if($wpdb->last_error !== '') :
    $wpdb->print_error();
endif;

2 - Output the error but do not log it

If you are not interested in logging the error, you can add your own my_print_error() funciton and use that instead of $wpdb->print_error() -

function my_print_error(){

    global $wpdb;

    if($wpdb->last_error !== '') :

        $str   = htmlspecialchars( $wpdb->last_result, ENT_QUOTES );
        $query = htmlspecialchars( $wpdb->last_query, ENT_QUOTES );

        print "<div id='error'>
        <p class='wpdberror'><strong>WordPress database error:</strong> [$str]<br />
        <code>$query</code></p>
        </div>";

    endif;

}

Last Edit: Syntax Mistake

Me daen blancoen $ string y $ query

Gives me blank in $str and $query
- 0
- 2018-07-15
Elmensaje deerrorestáen `$ wpdb-> last_error`,noen` $ wpdb-> last_result`.

The error message is in `$wpdb->last_error`, not in `$wpdb->last_result`.
- 2
- 2018-12-12
- Martin_W