为什么这个 MySQL 查询在 phpmyadmin 中有效，但在我的 php 脚本中没有返回任何内容？

Question

我在 phpmyadmin 中尝试了以下查询，它返回了正确的结果，但是当我尝试将结果传递给 php 中的变量时，该变量基本上是空的（即，当我尝试在带有 mysql_fetch_array 的 while 循环中使用它时，我什么也没得到。而 mysql_num_rows 只返回 1)。

这可能与我在 MySQL 中创建临时表有关吗？这是查询：

CREATE TEMPORARY TABLE solved
SELECT comments.nid FROM flag_content
LEFT JOIN comments ON flag_content.content_id=comments.cid
LEFT JOIN term_node ON term_node.nid=comments.nid
WHERE flag_content.fid=3 AND term_node.tid=522;

SELECT node.nid, node.title, users.name, node_counter.totalcount, node_comment_statistics.comment_count, node_comment_statistics.last_comment_timestamp
FROM node
LEFT JOIN term_node ON node.nid = term_node.nid
LEFT JOIN node_comment_statistics ON node.nid = node_comment_statistics.nid
LEFT JOIN node_counter ON node.nid = node_counter.nid
LEFT JOIN users ON node.uid = users.uid
LEFT JOIN solved ON node.nid=solved.nid
WHERE term_node.tid=522 AND solved.nid IS NULL;

我将此查询存储在 PHP 函数中：

function getPosts(){
   dbConnect(); //establishes connection
   //"....." in the following line is the above query
   return mysql_query(".......") or die("<b>A fatal MySQL error occured</b>.\n<br />Query: " . $query . "<br />\nError: (" . mysql_errno() . ") " . mysql_error()); 
}

调用它的代码行是：

$result = getPosts();

当我调用 getPosts() 时，查询因致命错误而终止。我得到相同错误的两个版本，具体取决于查询是否使用“。”跨多行连接。或者干脆写在一行上。

跨多行连接时出错：

Error: (1064) You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'comments.nid FROM flag_content LEFT JOIN comments ON flag_content.content_id=com' at line 1

单行写入时出错：

Error: (1064) You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'SELECT node.nid, node.title, users.name, node_counter.totalcount, node_comment_s' at line 1

Answer 1

尝试一次执行一个查询。创建临时表，选择其中，然后将其作为三个单独的查询删除。作为安全预防措施，sql socket 只允许一个执行块中的一个查询

它看起来像......

mysql_query("CREATE TEMPORARY TABLE solved
SELECT comments.nid FROM flag_content
LEFT JOIN comments ON flag_content.content_id=comments.cid
LEFT JOIN term_node ON term_node.nid=comments.nid
WHERE flag_content.fid=3 AND term_node.tid=522;");

$result = mysql_query("SELECT node.nid, node.title, users.name, node_counter.totalcount, node_comment_statistics.comment_count, node_comment_statistics.last_comment_timestamp
FROM node
LEFT JOIN term_node ON node.nid = term_node.nid
LEFT JOIN node_comment_statistics ON node.nid = node_comment_statistics.nid
LEFT JOIN node_counter ON node.nid = node_counter.nid
LEFT JOIN users ON node.uid = users.uid
LEFT JOIN solved ON node.nid=solved.nid
WHERE term_node.tid=522 AND solved.nid IS NULL;
");