Question

我正在尝试通过db列中包含的单词过滤sql查询。

这是有效的（请不要告诉我有错误......它不适用于哪里）

    $query = sprintf("SELECT *, ( 3959 * acos( cos( radians('%s') ) * cos( radians( `Lat` ) ) * cos( radians( `Long` ) - radians('%s') ) + sin( radians('%s') ) * sin( radians( `Lat` ) ) ) ) AS distance FROM Tutors HAVING distance < '%s' ORDER BY distance",
      mysql_real_escape_string($lat),
      mysql_real_escape_string($lng),
      mysql_real_escape_string($lat),
      mysql_real_escape_string($radius));
    $result = mysql_query($query, $dbConn);

我想添加以下内容：

    $query = sprintf("SELECT *, ( 3959 * acos( cos( radians('%s') ) * cos( radians( `Lat` ) ) * cos( radians( `Long` ) - radians('%s') ) + sin( radians('%s') ) * sin( radians( `Lat` ) ) ) ) AS distance FROM Tutors HAVING distance < '%s' AND SubjectList like '%s' ORDER BY distance",
      mysql_real_escape_string($lat),
      mysql_real_escape_string($lng),
      mysql_real_escape_string($lat),
      mysql_real_escape_string($radius),
      mysql_real_escape_string($subject));
    $result = mysql_query($query, $dbConn);

Answer 1

这是现在有效的解决方案 - 感谢大家的帮助

$query = "SELECT *, ( 3959 * acos( cos( radians('". addslashes($lat) ."') ) * cos( radians( `Lat` ) ) * cos( radians( `Long` ) - radians('". addslashes($lng) ."') ) + sin( radians('". addslashes($lat) ."') ) * sin( radians( `Lat` ) ) ) ) AS distance FROM Tutors WHERE `SubjectList` LIKE '%". addslashes($subject) ."%' GROUP BY distance HAVING distance < '". addslashes($radius) ."'";

Answer 2

你试过了吗？

SELECT *,(formula) AS distance FROM Tutors WHERE SubjectList LIKE '%s' ORDER BY distance HAVING distance < '%s'

WHERE作用于所有行，而HAVING作用于聚合函数，因此您需要确保首先减少了聚合公式所依据的集合。这也将产生更有效的查询。

HAVING vs. WHERE有时是一个非常棘手的区别，这个链接很好地描述了它：

http://blog.sqlauthority.com/2007/07/04/sql-server-definition-comparison-and-difference-between-having-and-where-clause/

php mysql查询喜欢（包含）

2 个答案: