最好使用以下查询来获取所有列名 很容易

显示tablename中的列

<?php
        $table = 'orders';
        $query = "SHOW COLUMNS FROM $table";
        if($output = mysql_query($query)):
            $columns = array();
            while($result = mysql_fetch_assoc($output)):
                $columns[] = $result['Field'];
            endwhile;
        endif;
        echo '<pre>';
        print_r($columns);
        echo '</pre>';
?>

您可以使用此查询查询特定数据库中每个表的所有列

select
    TABLE_SCHEMA,
    TABLE_NAME,
    COLUMN_NAME
from
    information_schema.columns
where
    table_schema = 'database_name'
order by 
    table_name,
    ordinal_position;

在Nicola的回答上加上一些可读的php

$a = mysqli_query($conn,"select * from information_schema.columns
where table_schema = 'your_db'
order by table_name,ordinal_position");
$b = mysqli_fetch_all($a,MYSQLI_ASSOC);
$d = array();
foreach($b as $c){
    if(!is_array($d[$c['TABLE_NAME']])){
        $d[$c['TABLE_NAME']] = array();
    }
    $d[$c['TABLE_NAME']][] = $c['COLUMN_NAME'];
}
echo "<pre>",print_r($d),"</pre>";

问题是:

是否有一个快速的方法，从MySQL所有表中获得所有的列名，而不必列出所有的表?

SQL来获取每列的所有信息

select * from information_schema.columns
where table_schema = 'your_db'
order by table_name,ordinal_position

获取所有的列名

select COLUMN_NAME from information_schema.columns
where table_schema = 'your_db'
order by table_name,ordinal_position

如果它对其他人有用，这将为您提供每个表中以逗号分隔的列列表:

SELECT table_name,GROUP_CONCAT(column_name ORDER BY ordinal_position)
FROM information_schema.columns
WHERE table_schema = DATABASE()
GROUP BY table_name
ORDER BY table_name

注意:在使用具有大量列和/或具有较长的字段名的表时，要注意group_concat_max_len限制，这可能导致数据被截断。