列出MySQL表中的所有字段:

select * 
  from information_schema.columns 
 where table_schema = 'your_DB_name' 
   and table_name = 'Your_tablename'

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

最好使用以下查询来获取所有列名 很容易

显示tablename中的列

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

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>";

类似于@suganya发布的答案，这并没有直接回答问题，但对于单个表来说是一个更快的选择:

DESCRIBE column_name;