Question

我目前正在尝试更新我的内部搜索引擎以使用多个单词。这是非常庞大和复杂但我遇到了错误，我现在从未遇到过错误，我不明白为什么。

所以问题是，为什么我收到以下错误？

我将把它分成不同的部分以便更好地理解。

这只是我echo的SQL查询，复制并粘贴到PHPMyAdmin，粘贴在这里（PHPMyAdmin很好地格式化）它在数据库中搜索2个单词：

SELECT *
FROM (

SELECT p.page_url AS url, COUNT( * ) AS occurrences
FROM PAGE p, word w, occurrence o
WHERE (
(
p.page_id = o.page_id
AND w.page_word_id = o.page_word_id
AND w.word_word LIKE '%' 'test' '%'
GROUP BY p.page_id
)
OR (
p.page_id = o.page_id
AND w.page_word_id = o.page_word_id
AND w.word_word LIKE '%' 'search' '%'
GROUP BY p.page_id
)
UNION (

SELECT f.file_url AS url, COUNT( * ) AS occurrences
FROM files f, filenames fn, fileoccurrence fo
WHERE f.file_id = fo.file_id
AND fn.file_word_id = fo.file_word_id
AND fn.file_word LIKE '%' 'test' '%'
GROUP BY f.file_id
)
OR (

SELECT f.file_url AS url, COUNT( * ) AS occurrences
FROM files f, filenames fn, fileoccurrence fo
WHERE f.file_id = fo.file_id
AND fn.file_word_id = fo.file_word_id
AND fn.file_word LIKE '%' 'search' '%'
GROUP BY f.file_id
)
)t
ORDER BY occurrences DESC

此代码由下面的PHP代码生成，该代码使用搜索输入中的explode函数

// Do a little formatting
$keyword = strtolower($keyword);

// Get timestamp for start
$start_time = microtime(true);

$searched_words = explode(' ', $keyword);

foreach ($searched_words as $index => $word) {
    // Set up the stemmer
    $stemmer = new PorterStemmer;
    $stemmed_string = $stemmer->stem($word);
    $searched_words[$index] = $stemmed_string;
}

//  Configure the sql code
$sql = "SELECT * FROM (SELECT p.page_url AS url, COUNT(*) AS occurrences 
    FROM page p, word w, occurrence o WHERE (";

// Add the extra words to the sql
foreach ($searched_words as $index => $word) {  
    $sql .= "(p.page_id = o.page_id AND w.page_word_id = o.page_word_id
        AND w.word_word LIKE '%' '" . $word . "' '%' GROUP BY p.page_id) OR";
}
// Add the union to the sql and then add the second query   
$sql = substr($sql, 0, (strLen($sql)-3)); //this will eat the last OR
$sql .= " UNION ";

// The second set of querys
foreach ($searched_words as $index => $word) {
    $sql .= "(SELECT f.file_url AS url, COUNT(*) AS occurrences FROM files f, filenames fn, fileoccurrence fo
        WHERE f.file_id = fo.file_id AND fn.file_word_id = fo.file_word_id AND fn.file_word
        LIKE '%' '" . $word . "' '%' GROUP BY f.file_id) OR";
}

// Clsoe the sql code
$sql = substr($sql, 0, (strLen($sql)-3)); //this will eat the last OR
$sql .= ") t ORDER BY occurrences DESC"; // LIMIT " . $results . "");

// echo the query for the pure lolz of it
echo $sql . "<br /><br />";

// Search the DB for the results
$results = mysql_query($sql)
    or die("Invalid query: " . mysql_error());

所有这些都会返回错误：

查询无效：您的SQL语法出错;检查手册对应于您的MySQL服务器版本，以获得正确的语法在'GROUP BY p.page_id）附近使用或（p.page_id = o.page_id AND 第3行的w.page_word_id = o.page_word_id'

为什么我收到此错误？我之前使用的代码工作得很好。我添加的唯一真实内容是foreach()。

这是我原来的SQL代码：

$result = mysql_query("SELECT * FROM (SELECT p.page_url AS url, COUNT(*) AS occurrences 
    FROM page p, word w, occurrence o WHERE p.page_id = o.page_id AND w.page_word_id = o.page_word_id
    AND w.word_word LIKE '%' '" . $stemmed_string . "' '%' GROUP BY p.page_id UNION  
    SELECT f.file_url AS url, COUNT(*) AS occurrences FROM files f, filenames fn, fileoccurrence fo
    WHERE f.file_id = fo.file_id AND fn.file_word_id = fo.file_word_id AND fn.file_word
    LIKE '%' '" . $stemmed_string . "' '%' GROUP BY f.file_id) t ORDER BY occurrences DESC") // LIMIT " . $results . "")
        or die("Invalid query: " . mysql_error());

编辑：修正了上述错误。使用此代码

//  Configure the sql code
$sql = "SELECT * FROM (SELECT p.page_url AS url, COUNT(*) AS occurrences 
    FROM page p, word w, occurrence o WHERE (";

// Add the extra words to the sql
foreach ($searched_words as $index => $word) {  
    $sql .= "(p.page_id = o.page_id AND w.page_word_id = o.page_word_id
        AND w.word_word LIKE CONCAT('%', '" . $word . "', '%'))) OR "; //GROUP BY p.page_id)
}
// Add the union to the sql and then add the second query   
$sql = substr($sql, 0, (strLen($sql)-4)); //this will eat the last OR
$sql .= " GROUP BY p.page_id)";
$sql .= " UNION ";
$sql .= "(SELECT f.file_url AS url, COUNT(*) AS occurrences FROM files f, filenames fn, fileoccurrence fo
    WHERE (";

// The second set of querys
foreach ($searched_words as $index => $word) {
    $sql .= "(f.file_id = fo.file_id AND fn.file_word_id = fo.file_word_id AND fn.file_word
        LIKE CONCAT('%', '" . $word . "', '%'))) OR "; //GROUP BY f.file_id)
}

// Clsoe the sql code
$sql = substr($sql, 0, (strLen($sql)-4)); //this will eat the last OR
$sql .= " GROUP BY f.file_id)";
$sql .= ") t ORDER BY occurrences DESC"; // LIMIT " . $results . "");

现在产生错误：

无效查询：每个派生表都必须有自己的别名

与工会有关（我不擅长工会......或者一般的SQL）

Answer 1

只能将SQL中的字符串放在一起，就不能在SQL中连接它们。

AND w.word_word LIKE '%' 'test' '%'

应该是

AND w.word_word LIKE CONCAT('%', 'test', '%')

或者，如果使用SET SQL_MODE='PIPES_AS_CONCAT'获取标准ANSI SQL语法，则可以使用：

AND w.word_word LIKE '%' || 'test' || '%'

重新评论，我看到另一个问题：

在SQL中，必须先完成WHERE子句，然后才能添加GROUP BY子句。语法是：

WHERE ( <conditions...> )
GROUP BY <expressions>

你有：

WHERE ( <conditions...> GROUP BY <expressions> ) 
   OR ( <conditions...> GROUP BY <expressions> )

你拥有的不是合法的语法。

真的，这是你应该能够在SQL的任何初学者参考资料中查找的东西。

每个派生表都必须有自己的别名

这意味着您在FROM子句中使用了子查询但没有给它别名。例如：

SELECT ... FROM (SELECT ... FROM table) AS x WHERE ...etc...

如果省略AS x，则表示错误（在这种情况下，x只是一个示例，您可以选择更有意义的别名）。

Answer 2

在生成的SQL中，括号不匹配...有9'（'s和8'）。

您是否也将LIMIT " . $results . "");评论为上次代码更改的一部分？

巨大的SQL查询返回错误（mysql）

2 个答案: