$ wpdb-> get_row（）只返回一行？

实际上,仅在希望获得一个结果时才使用get_row(),否则可以使用get_results()

Indeed, use get_row() only when you expect to get one result, else you can use get_results()

有三种方法可以从数据库中提取数据.

1. $wpdb->get_var:使用它从数据库表中获取单个值.就像您要计算评论总数一样.您可以按照以下方式进行操作:

 <?php 
$comment_count = $wpdb->get_var($wpdb->prepare("SELECT COUNT(*) FROM $wpdb->comments;")); 
echo '<p>Total comments: ' . $comment_count . '</p>';
?>
 

2. $wpdb->get_row:要检索整个表行,可以使用它.

示例:

 <?php 
$thepost = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $wpdb->posts WHERE ID = 1" ) );
echo $thepost->post_title; 
?>
 

OR

 <?php 
$thepost = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $wpdb->posts WHERE ID = 1" ), ARRAY_A );
print_r ($thepost); 
?>
 

通过在get_row中使用ARRAY_A参数,您的帖子数据将作为关联数组返回.另外,您可以使用ARRAY_N参数以数字索引数组返回您的帖子数据.

3. $wpdb->get_results:标准SELECT查询应使用get_results函数从数据库中检索多行数据.

 <?php 
global $wpdb;
$allposts = $wpdb->get_results( $wpdb->prepare("SELECT ID, post_title FROM $wpdb->posts WHERE post_status = 'publish'") );
foreach ($allposts as $singlepost) { 
         echo '<p>' .$singlepost->post_title. '</p>';
}
?>
 

,并且您需要最后一个.

There are three ways to pull data from the database.

1.$wpdb->get_var:use this to get a single value from the database table. Like if you want to count the total number of comments. You can do it in following way:

<?php 
$comment_count = $wpdb->get_var($wpdb->prepare("SELECT COUNT(*) FROM $wpdb->comments;")); 
echo '<p>Total comments: ' . $comment_count . '</p>';
?>

2.$wpdb->get_row : To retrieve an entire table row you can use this.

Example:

<?php 
$thepost = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $wpdb->posts WHERE ID = 1" ) );
echo $thepost->post_title; 
?>

OR

<?php 
$thepost = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $wpdb->posts WHERE ID = 1" ), ARRAY_A );
print_r ($thepost); 
?>

By using the ARRAY_A parameter in get_row your post data is returned as an associative array. Alternatively, you could use the ARRAY_N parameter to return your post data in a numerically indexed array.

3.$wpdb->get_results:Standard SELECT queries should use the get_results function for retrieving multiple rows of data from the database.

<?php 
global $wpdb;
$allposts = $wpdb->get_results( $wpdb->prepare("SELECT ID, post_title FROM $wpdb->posts WHERE post_status = 'publish'") );
foreach ($allposts as $singlepost) { 
         echo '<p>' .$singlepost->post_title. '</p>';
}
?>

and you need the last one, as you can expect.

 $wpdb->get_row('query', output_type, row_offset);
 

行偏移 (整数)所需的行(0为第一行).默认为0.

va http://codex.wordpress.org/Class_Reference/wpdb

$wpdb->get_row('query', output_type, row_offset);

row_offset (integer) The desired row (0 being the first). Defaults to 0.

va http://codex.wordpress.org/Class_Reference/wpdb

我的解决方法很简单.

 <?php
function count_results() {
    # use the data base
    global $wpdb;

    # Query to count all results from one table
    $sql_count_results = '
        SELECT count(*) as count
        FROM `YOUR_TABLE`;';

    # Ejecute function
    $results = $wpdb->get_row( $sql_count_results , OBJECT );

    # Return results
    return $results->count;
}
 

使用:

 <?php
echo count_results();
 

my solution is simple..

<?php
function count_results() {
    # use the data base
    global $wpdb;

    # Query to count all results from one table
    $sql_count_results = '
        SELECT count(*) as count
        FROM `YOUR_TABLE`;';

    # Ejecute function
    $results = $wpdb->get_row( $sql_count_results , OBJECT );

    # Return results
    return $results->count;
}

Use:

<?php
echo count_results();