如何在mysql中获得单词不超过40个字符的列 - How do you get columns in mysql that has no word greater than 40 characters?

How do you get columns in mysql that has no word greater than 40 characters?

基本上，我正在尝试在php中创建一个函数，该函数将为我提供最新的列（消息），该列的单词不超过40个字符。我能够获得最新的消息，但我不知道如何只获得单词不超过40个字符的最新消息。请参阅$callrecent变量。

<?php
function recentpost($postnum) {
$callrecent = "SELECT message FROM messages WHERE message (HAS NO WORD GREATER THAN 40 CHARACTERS) ORDER BY msg_id DESC LIMIT $postnum,1";
$callrecent_run = mysql_fetch_assoc(mysql_query($callrecent));
$message = stripslashes($callrecent_run['message']);
return $message;
}
?>

您可以使用正则表达式

SELECT message
FROM messages
WHERE message not regexp '[[:alnum:]]{41}'
ORDER BY msg_id DESC
LIMIT $postnum, 1

尝试

  SELECT message
    FROM messages
   WHERE LENGTH(message) <= 40
ORDER BY msg_id DESC
   LIMIT $postnum, 1