實現 PHP strip_tags 函數的功能。

		
CREATE DEFINER=`dba`@`%` FUNCTION `strip_tags`(`$str` TEXT)
RETURNS text CHARSET utf8
LANGUAGE SQL
NOT DETERMINISTIC
CONTAINS SQL
SQL SECURITY DEFINER
COMMENT ''
BEGIN
    DECLARE $start, $end INT DEFAULT 1;
    LOOP
        SET $start = LOCATE("<", $str, $start);
        IF (!$start) THEN RETURN $str; END IF;
        SET $end = LOCATE(">", $str, $start);
        IF (!$end) THEN SET $end = $start; END IF;
        SET $str = INSERT($str, $start, $end - $start + 1, "");
    END LOOP;
END		
		
		

		
mysql> select strip_tags('<span><i>hello</i> <b>world</b>!!! <br /><a href="//www.netkiller/">netkiller</a>');
+----------------------------------------------------------------------+
| strip_tags('<span>hel<b>lo <a href="world">wo<>rld</a> <<x>again<.') |
+----------------------------------------------------------------------+
| hello world again.                                                   |
+----------------------------------------------------------------------+
1 row in set

mysql> select strip_tags('<span style="color:red"><i>hello</i> <b id="world" >world</b>!!! <br /><a class="home" href="//www.netkiller/">netkiller</a><span>') as TEXT;
+--------------------------+
| TEXT                     |
+--------------------------+
| hello world!!! netkiller |
+--------------------------+
1 row in set (0.00 sec)