【发布时间】：2010-05-28 02:44:05
【问题描述】：
请先执行以下查询进行设置，以便您帮助我：-
CREATE TABLE IF NOT EXISTS `Tutor_Details` (
`id_tutor` int(10) NOT NULL auto_increment,
`firstname` varchar(100) NOT NULL default '',
`surname` varchar(155) NOT NULL default '',
PRIMARY KEY (`id_tutor`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=41 ;
INSERT INTO `Tutor_Details` (`id_tutor`,`firstname`, `surname`) VALUES
(1, 'Sandeepan', 'Nath'),
(2, 'Bob', 'Cratchit');
CREATE TABLE IF NOT EXISTS `Classes` (
`id_class` int(10) unsigned NOT NULL auto_increment,
`id_tutor` int(10) unsigned NOT NULL default '0',
`class_name` varchar(255) default NULL,
PRIMARY KEY (`id_class`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=229 ;
INSERT INTO `Classes` (`id_class`,`class_name`, `id_tutor`) VALUES
(1, 'My Class', 1),
(2, 'Sandeepan Class', 2);
CREATE TABLE IF NOT EXISTS `Tags` (
`id_tag` int(10) unsigned NOT NULL auto_increment,
`tag` varchar(255) default NULL,
PRIMARY KEY (`id_tag`),
UNIQUE KEY `tag` (`tag`),
KEY `id_tag` (`id_tag`),
KEY `tag_2` (`tag`),
KEY `tag_3` (`tag`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=18 ;
INSERT INTO `Tags` (`id_tag`, `tag`) VALUES
(1, 'Bob'),
(6, 'Class'),
(2, 'Cratchit'),
(4, 'Nath'),
(3, 'Sandeepan'),
(5, 'My');
CREATE TABLE IF NOT EXISTS `Tutors_Tag_Relations` (
`id_tag` int(10) unsigned NOT NULL default '0',
`id_tutor` int(10) default NULL,
KEY `Tutors_Tag_Relations` (`id_tag`),
KEY `id_tutor` (`id_tutor`),
KEY `id_tag` (`id_tag`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
INSERT INTO `Tutors_Tag_Relations` (`id_tag`, `id_tutor`) VALUES
(3, 1),
(4, 1),
(1, 2),
(2, 2);
CREATE TABLE IF NOT EXISTS `Class_Tag_Relations` (
`id_tag` int(10) unsigned NOT NULL default '0',
`id_class` int(10) default NULL,
`id_tutor` int(10) NOT NULL,
KEY `Class_Tag_Relations` (`id_tag`),
KEY `id_class` (`id_class`),
KEY `id_tag` (`id_tag`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
INSERT INTO `Class_Tag_Relations` (`id_tag`, `id_class`, `id_tutor`) VALUES
(5, 1, 1),
(6, 1, 1),
(3, 2, 2),
(6, 2, 2);
- 在我提供的当前系统数据中，名为“Sandeepan Nath”的导师创建了名为“My Class”的班级，名为“Bob Cratchit”的导师创建了名为“Sandeepan Class”的班级。
要求-
执行一个对结果有限制的查询，以按照搜索关键字的 AND 逻辑显示搜索结果，如下所示：-
- 如果搜索“Sandeepan Class”，则返回 Tutor Details 表中的 Tutor Sandeepan Nath 记录（因为“Sandeepan”是 Sandeepan Nath 的名字，而 Class 存在于 Sandeepan 班级的班级名称中）
- 如果搜索“Class”，则从 Tutor_details 表中提取两个导师，因为 Class 出现在两个导师创建的班级的名称中。
以下是我迄今为止所取得的成就（PHP Mysql）：-
<?php
$searchTerm1 = "Sandeepan";
$searchTerm2 = "Class";
mysql_select_db("test");
$sql = "SELECT td.*
FROM Tutor_Details AS td
LEFT JOIN Tutors_Tag_Relations AS ttagrels ON td.id_tutor = ttagrels.id_tutor
LEFT JOIN Classes AS wc ON td.id_tutor = wc.id_tutor
LEFT JOIN Class_Tag_Relations AS wtagrels ON td.id_tutor = wtagrels.id_tutor
LEFT JOIN Tags as t1 on ((t1.id_tag = ttagrels.id_tag) OR (t1.id_tag = wtagrels.id_tag))
LEFT JOIN Tags as t2 on ((t2.id_tag = ttagrels.id_tag) OR (t2.id_tag = wtagrels.id_tag))
where t1.tag LIKE '%".$searchTerm1."%'
AND t2.tag LIKE '%".$searchTerm2."%'
GROUP BY td.id_tutor
LIMIT 10
";
$result = mysql_query($sql);
echo $sql;
if($result)
{
while($rec = mysql_fetch_object($result)) $recs[] = $rec;
//$rec = mysql_fetch_object($result);
echo "<br><br>";
if(is_array($recs))
{
foreach($recs as $each)
{
print_r($each);
echo "<br>";
}
}
}
?>
但结果是：-
如果搜索“Sandeepan Nath”，它不会返回任何导师（而不仅仅是 Sandeepan 的行） 如果搜索“Sandeepan Class”，则返回 Sandeepan 的行（而不是 Bothutors ） 如果搜索“Bob Class”，则正确返回 Bob 的行 如果搜索“Bob Cratkit”，它不会返回任何导师（而不仅仅是
【问题讨论】：
标签： php mysql query-optimization