Como devolver o número de linhas encontradas da consulta Selecionar

Question

Como devolver o número de linhas encontradas da consulta Selecionar

16

83499 2014-01-29

Euescrevi umafunção que deve retornar onúmero de linhasencontradasem uma consulta selecionada,mas sempreparece retornar 0 ou umamatriz. Eutenhomexido comissopor cerca de uma hora agorae eu aindanão consigo descobrir! Tenho certeza de queestoufazendo algoestupidamenteerrado.

atabelamysql

 +--------+-------------+---------------------+
| postid |     ip      |        time         |
+--------+-------------+---------------------+
|   1234 | 192.168.0.1 | 2014-01-29 14:27:02 |
|   5678 | 192.168.0.2 | 2014-01-29 14:27:02 |
+--------+-------------+---------------------+

php

 ### Search for IP in database
function postviews_get_ip($id, $ip) {
    global $post, $wpdb;

    $wpdb->get_results("SELECT * FROM $wpdb->wp_postviews_ips WHERE postid = $id AND ip = $ip");

    $rowcount = $wpdb->num_rows;

    return $rowcount;
}

postviews_get_ip($id, $_SERVER['REMOTE_ADDR']);
//both $id and $_SERVER['REMOTE_ADDR']) return the values I'm searching for in the database

I wrote a function which is supposed to return the number of rows found in a SELECT query but it always either seems to return 0 or an array. I have been messing around with this for about an hour now and I still can't figure it out! I'm sure I'm doing something stupidly wrong.

The MySQL Table

+--------+-------------+---------------------+
| postid |     ip      |        time         |
+--------+-------------+---------------------+
|   1234 | 192.168.0.1 | 2014-01-29 14:27:02 |
|   5678 | 192.168.0.2 | 2014-01-29 14:27:02 |
+--------+-------------+---------------------+

PHP

### Search for IP in database
function postviews_get_ip($id, $ip) {
    global $post, $wpdb;

    $wpdb->get_results("SELECT * FROM $wpdb->wp_postviews_ips WHERE postid = $id AND ip = $ip");

    $rowcount = $wpdb->num_rows;

    return $rowcount;
}

postviews_get_ip($id, $_SERVER['REMOTE_ADDR']);
//both $id and $_SERVER['REMOTE_ADDR']) return the values I'm searching for in the database

fonte
Swen

- Qual é onome databelae oprefixo databela?
  
  What is the name of the table and the table prefix?
  - 0
  - 2014-01-29
  - Chittaranjan
- @Chittaranjan Nome databela é WP_POSTVIMES_IPS,nãotenho certeza do que você quer dizer comprefixo demesaembora.
  
  @Chittaranjan Table name is wp_postviews_ips, I'm not sure what you mean by table prefix though.
  - 0
  - 2014-01-29
  - Swen
- Removendo "$ WPDB->" de $ WPDB-> WP_POSTVIMES_IPSpareciafazer otruque!
  
  Removing "$wpdb->" from $wpdb->wp_postviews_ips seemed to do the trick!
  - 0
  - 2014-01-29
  - Swen
- Essa é a razãopela qualeutinhapedido onome damesae prefixo.Todas astabelas do WordPresstêm umprefixo que você define durante a configuração do site do WordPress.Aquiestãomais detalhes sobre [CODEX] (http://codex.wordpress.org/creating_tables_with_plugins#database_table_prefix) Porfavor,verifiqueminha resposta atualizada com o uso correto donome databela.
  
  That's the reason I had asked for the table name and prefix. All wordpress tables have a prefix which you set during setting up the wordpress site. Here are more details on [codex](http://codex.wordpress.org/Creating_Tables_with_Plugins#Database_Table_Prefix) Please check my updated answer with correct use of table name.
  - 0
  - 2014-01-29
  - Chittaranjan

2 respostas

votos

- 2
- 2014-01-29
Parece que a consultaestáerrada. $ IP é stringpara que você deve colocar uma única citação ao redor que abaixo

$ wpdb- >get_results ("Select *from {$ wpdb- >prefix}postviews_ips ondepostid=$ IDe IP='$ip'");
Seems the query is wrong. $ip is string so you should put single quote around that as below

$wpdb->get_results("SELECT * FROM {$wpdb->prefix}postviews_ips WHERE postid = $id AND ip = '$ip'");
- Tenteiissoe ainda retorna 0.
  
  Tried this and it still returns 0.
  - 0
  - 2014-01-29
  - Swen

eteich · Accepted Answer · 2014-01-29

29

2014-01-29

Se vocêestá apenastentando obter uma contagem,$wpdb->get_var();junto com o uso COUNT()no seu SQL serámelhor:

.

 ### Search for IP in database
function postviews_get_ip($id, $ip) {
    global $post, $wpdb;

    $rowcount = $wpdb->get_var("SELECT COUNT(*) FROM $wpdb->wp_postviews_ips WHERE postid = $id AND ip = '$ip'");

    return $rowcount;
}

postviews_get_ip($id, $_SERVER['REMOTE_ADDR']);
//both $id and $_SERVER['REMOTE_ADDR']) return the values I'm searching for in the database

Quanto ao que deuerradono seuexemplo anterior,vocênãoestava atribuindo seu $wpdb->get_results()instância a uma variávele semela $wpdb->num_rows; vai apenas retornar zero,poisnãoestápuxando dainstância da consulta,mas sim o objetoglobal $ WBDB.

Se você quiser usar get_results():

 ### Search for IP in database
function postviews_get_ip($id, $ip) {
    global $post, $wpdb;

    $ipquery= $wpdb->get_results("SELECT * FROM $wpdb->wp_postviews_ips WHERE postid = $id AND ip = '$ip'");
    $rowcount = $ipquery->num_rows;
    return $rowcount;
}

postviews_get_ip($id, $_SERVER['REMOTE_ADDR']);
//both $id and $_SERVER['REMOTE_ADDR']) return the values I'm searching for in the database

maseunão veria anecessidade disso,amenos que vocêprecise dos resultados,casoem queeu apenas devolveria o objeto $ipquerye usar num_rowsnele quando Euprecisava disso:

 ### Search for IP in database
function postviews_get_ip($id, $ip) {
    global $post, $wpdb;

    $ipquery = $wpdb->get_results("SELECT * FROM $wpdb->wp_postviews_ips WHERE postid = $id AND ip = '$ip'");
    return $ipquery;
}

$someVariable = postviews_get_ip($id, $_SERVER['REMOTE_ADDR']);
//both $id and $_SERVER['REMOTE_ADDR']) return the values I'm searching for in the database

echo $someVariable->num_rows;

If you are merely trying to get a count, $wpdb->get_var(); along with using COUNT() in your sql will be better:

### Search for IP in database
function postviews_get_ip($id, $ip) {
    global $post, $wpdb;

    $rowcount = $wpdb->get_var("SELECT COUNT(*) FROM $wpdb->wp_postviews_ips WHERE postid = $id AND ip = '$ip'");

    return $rowcount;
}

postviews_get_ip($id, $_SERVER['REMOTE_ADDR']);
//both $id and $_SERVER['REMOTE_ADDR']) return the values I'm searching for in the database

As to what went wrong in your previous example, you weren't assigning your $wpdb->get_results() instance to a variable, and without it $wpdb->num_rows; is just going to return zero as it isn't actually pulling from the instance of the query, but rather the global $wbdb object.

If you do want to use get_results():

### Search for IP in database
function postviews_get_ip($id, $ip) {
    global $post, $wpdb;

    $ipquery= $wpdb->get_results("SELECT * FROM $wpdb->wp_postviews_ips WHERE postid = $id AND ip = '$ip'");
    $rowcount = $ipquery->num_rows;
    return $rowcount;
}

postviews_get_ip($id, $_SERVER['REMOTE_ADDR']);
//both $id and $_SERVER['REMOTE_ADDR']) return the values I'm searching for in the database

But I wouldn't see the need for that unless you needed the results, in which case I would just return the $ipquery object and use num_rows on it when I needed it:

### Search for IP in database
function postviews_get_ip($id, $ip) {
    global $post, $wpdb;

    $ipquery = $wpdb->get_results("SELECT * FROM $wpdb->wp_postviews_ips WHERE postid = $id AND ip = '$ip'");
    return $ipquery;
}

$someVariable = postviews_get_ip($id, $_SERVER['REMOTE_ADDR']);
//both $id and $_SERVER['REMOTE_ADDR']) return the values I'm searching for in the database

echo $someVariable->num_rows;

fonte
eteich

Pequena adição.Você deve sempre usar Prepare (https://developer.wordpress.org/reference/classes/wpdb/prepare/) aoexecutar quaisquer consultasparaevitar ainjeção SQL.

Small addition. You should always use prepare (https://developer.wordpress.org/reference/classes/wpdb/prepare/) when executing any queries to prevent sql injection.
- 1
- 2019-05-29
- Maciej Paprocki
Na verdade,quenão deve ser umapequena adição,isso émuitoimportanteparanãotornar seu códigoexplorável viainjeção SQL.

Actually that shouldnt be a small addition, that's very important not to make your code exploitable via sql injection.
- 0
- 2019-09-12
- Max Carroll