这是一个生产的PHP / MySQL系统，已经运行了几个月，大多没有问题。
很偶然，就像每隔几周一次，我看到＆＃34;无法保存结果集＆＃34;来自MySQL查询的错误。
我知道这可能是由一个大的结果集引起的，但这不是这里的情况。在最近的例子中，它发生在通常不超过10行的小表中（行表示活动游戏，并且在游戏结束后它们被移除 - 大量转换，但总是很小）。
查询非常简单：
SELECT player_1_id, player_2_id FROM minuetServer_games
WHERE ( player_1_id = '1513399' OR player_2_id = '1513399' )
AND last_action_time < SUBTIME( CURRENT_TIMESTAMP, '0 0:01:22.000' )
FOR UPDATE;
此查询的目的是为给定的user_id（它们可以是p1或p2）找到任何不太陈旧的活动游戏。如果存在，我在下一个查询中更新了他们游戏的last_action_time（当然，当结果集未被保存时，更新就不会发生）。
我运行了CHECK TABLE，结果没问题。
虚假，偶尔会出现什么原因？＃34;无法保存结果集＆＃34;警告？有办法解决吗？有一个坚实的解决方案吗？
编辑：
评论者要求提供有关他PHP配置的更多信息。这是phpinfo（）输出的直接链接：
http://cordialminuet.com/info.php
EDIT2：
这是创建查询的代码：
global $tableNamePrefix;
cm_queryDatabase( "SET AUTOCOMMIT=0" );
global $moveTimeLimit;
$query = "SELECT player_1_id, player_2_id ".
"FROM $tableNamePrefix"."games ".
"WHERE ( player_1_id = '$user_id' OR player_2_id = '$user_id' ) ".
" AND last_action_time < ".
" SUBTIME( CURRENT_TIMESTAMP, '$moveTimeLimit' ) FOR UPDATE;";
// watch for deadlock here and retry
$result = cm_queryDatabase( $query, 0 );
这里是cm_queryDatabase的代码：
function cm_queryDatabase( $inQueryString, $inDeadlockFatal=1 ) {
global $cm_mysqlLink;
if( gettype( $cm_mysqlLink ) != "resource" ) {
// not a valid mysql link?
cm_connectToDatabase();
}
$result = mysql_query( $inQueryString, $cm_mysqlLink );
// a bunch of error handling here if $result is FALSE
// ......
// then finally
return $result;
}
这里是cm_connectToDatabase的代码：
function cm_connectToDatabase( $inTrackStats = true) {
global $databaseServer,
$databaseUsername, $databasePassword, $databaseName,
$cm_mysqlLink;
$cm_mysqlLink =
mysql_connect( $databaseServer,
$databaseUsername, $databasePassword );
// bunch of error handling if $cm_mysqlLink is false
// ....
}
请注意＆＃34;无法保存结果集＆＃34;是mysql_query抛出的警告。此外，该查询每天运行数百次而没有问题。这个警告最多每隔几周发生一次。这是几天前最新的堆栈跟踪：
Warning: mysql_query() [<a href='function.mysql-query'>function.mysql-query</a>]: Unable to save result set in /home/jcr14/public_html/gameServer/server.php on line 11248
#0 cm_noticeAndWarningHandler(2, mysql_query() [<a href='function.mysql-query'>function.mysql-query</a>]: Unable to save result set, /home/jcr14/public_html/gameServer/server.php, 11248, Array ([inQueryString] => SELECT player_1_id, player_2_id FROM minuetServer_games WHERE ( player_1_id = '1513399' OR player_2_id = '1513399' ) AND last_action_time < SUBTIME( CURRENT_TIMESTAMP, '0 0:01:22.000' ) FOR UPDATE;,[inDeadlockFatal] => 0,[cm_mysqlLink] => Resource id #4))
#1 mysql_query(SELECT player_1_id, player_2_id FROM minuetServer_games WHERE ( player_1_id = '1513399' OR player_2_id = '1513399' ) AND last_action_time < SUBTIME( CURRENT_TIMESTAMP, '0 0:01:22.000' ) FOR UPDATE;, Resource id #4) called at [/home/jcr14/public_html/gameServer/server.php:11248]
#2 cm_queryDatabase(SELECT player_1_id, player_2_id FROM minuetServer_games WHERE ( player_1_id = '1513399' OR player_2_id = '1513399' ) AND last_action_time < SUBTIME( CURRENT_TIMESTAMP, '0 0:01:22.000' ) FOR UPDATE;, 0) called at [/home/jcr14/public_html/gameServer/server.php:5979]
我会在服务器日志中查看过去几个月的其他示例。
编辑3：
在过去30天（我刷新旧日志条目），这已经发生了五次。其中四次出现在上述查询中。有一次发生在另一个查询中：
SELECT next_magic_square_seed % 4294967296
FROM minuetServer_server_globals FOR UPDATE;
这一天也被称为100次，没有问题。这是一个包含单行的表。
周围的代码：
function cm_getNewSquare() {
global $tableNamePrefix;
// have it wrap around at the 32-bit unsigned max
// because getMagicSquare6 takes a 32-bit unsigned seed.
// we store it as a BIGINT to keep it from getting stuck on the same
// square after four billion games
$query = "SELECT next_magic_square_seed % 4294967296 ".
"FROM $tableNamePrefix".
"server_globals FOR UPDATE;";
$result = cm_queryDatabase( $query );
编辑4：
表格结构：
mysql> describe minuetServer_games;
+-----------------------+---------------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-----------------------+---------------------+------+-----+---------+----------------+
| game_id | bigint(20) unsigned | NO | PRI | NULL | auto_increment |
| creation_time | datetime | NO | | NULL | |
| last_action_time | datetime | NO | | NULL | |
| player_1_id | int(10) unsigned | NO | MUL | NULL | |
| player_2_id | int(10) unsigned | NO | MUL | NULL | |
| dollar_amount | decimal(11,2) | NO | MUL | NULL | |
| amulet_game | tinyint(3) unsigned | NO | MUL | NULL | |
| amulet_game_wait_time | datetime | NO | MUL | NULL | |
| started | tinyint(3) unsigned | NO | | NULL | |
| round_number | int(10) unsigned | NO | | NULL | |
| game_square | char(125) | NO | | NULL | |
| player_1_got_start | tinyint(4) | NO | | NULL | |
| player_2_got_start | tinyint(4) | NO | | NULL | |
| player_1_moves | char(13) | NO | | NULL | |
| player_2_moves | char(13) | NO | | NULL | |
| player_1_bet_made | tinyint(3) unsigned | NO | | NULL | |
| player_2_bet_made | tinyint(3) unsigned | NO | | NULL | |
| player_1_ended_round | tinyint(3) unsigned | NO | | NULL | |
| player_2_ended_round | tinyint(3) unsigned | NO | | NULL | |
| move_deadline | datetime | NO | | NULL | |
| player_1_coins | tinyint(3) unsigned | NO | | NULL | |
| player_2_coins | tinyint(3) unsigned | NO | | NULL | |
| player_1_pot_coins | tinyint(3) unsigned | NO | | NULL | |
| player_2_pot_coins | tinyint(3) unsigned | NO | | NULL | |
| settled_pot_coins | tinyint(3) unsigned | NO | | NULL | |
| semaphore_key | int(10) unsigned | NO | | NULL | |
+-----------------------+---------------------+------+-----+---------+----------------+
26 rows in set (0.00 sec)
CREATE语句：
"CREATE TABLE $tableName(" .
"game_id BIGINT UNSIGNED NOT NULL PRIMARY KEY AUTO_INCREMENT," .
"creation_time DATETIME NOT NULL,".
"last_action_time DATETIME NOT NULL,".
"player_1_id INT UNSIGNED NOT NULL," .
"INDEX( player_1_id )," .
"player_2_id INT UNSIGNED NOT NULL," .
"INDEX( player_2_id )," .
"dollar_amount DECIMAL(11, 2) NOT NULL,".
"INDEX( dollar_amount )," .
"amulet_game TINYINT UNSIGNED NOT NULL,".
"INDEX( amulet_game ),".
// wait for a random amount of time before
// settling on an opponent for an amulet game
"amulet_game_wait_time DATETIME NOT NULL,".
"INDEX( amulet_game_wait_time ),".
"started TINYINT UNSIGNED NOT NULL,".
"round_number INT UNSIGNED NOT NULL," .
// 36-cell square, numbers from 1 to 36, separated by #
// character
"game_square CHAR(125) NOT NULL,".
// flag set when each player requests the very first game
// state. This indicates that both are aware that the game
// has started, so leave penalties can be assessed
"player_1_got_start TINYINT NOT NULL,".
"player_2_got_start TINYINT NOT NULL,".
"player_1_moves CHAR(13) NOT NULL,".
"player_2_moves CHAR(13) NOT NULL,".
"player_1_bet_made TINYINT UNSIGNED NOT NULL,".
"player_2_bet_made TINYINT UNSIGNED NOT NULL,".
"player_1_ended_round TINYINT UNSIGNED NOT NULL,".
"player_2_ended_round TINYINT UNSIGNED NOT NULL,".
"move_deadline DATETIME NOT NULL,".
"player_1_coins TINYINT UNSIGNED NOT NULL, ".
"player_2_coins TINYINT UNSIGNED NOT NULL, ".
"player_1_pot_coins TINYINT UNSIGNED NOT NULL, ".
"player_2_pot_coins TINYINT UNSIGNED NOT NULL, ".
// coins in both pots that are common knowledge to both players
// (coins that have been matched by opponent to move on
// to next turn)
"settled_pot_coins TINYINT UNSIGNED NOT NULL, ".
"semaphore_key INT UNSIGNED NOT NULL ) ENGINE = INNODB;"
答案 0 :(得分：5)
虚假的，偶尔的“无法保存结果集”警告的原因是什么？
遗憾的是，PHP手册中没有详细记录此错误。那么，让我们的RTFS！
查看您的ext/mysql版本的源代码，错误"Unable to save result set" appears only once：
if(use_store == MYSQL_USE_RESULT) {
mysql_result=mysql_use_result(mysql->conn);
} else {
mysql_result=mysql_store_result(mysql->conn);
}
if (!mysql_result) {
if (PHP_MYSQL_VALID_RESULT(mysql->conn)) { /* query should have returned rows */
php_error_docref(NULL TSRMLS_CC, E_WARNING, "Unable to save result set");
查看PHP_MYSQL_VALID_RESULT宏的the definition：
#define PHP_MYSQL_VALID_RESULT(mysql) \
(mysql_field_count(mysql)>0)
很明显，出现此错误时，mysql_store_result()必须返回NULL，mysql_field_count()必须返回正数。后一个函数的MySQL C API documentation表示：
此函数的正常用法是
mysql_store_result()返回NULL时（因此您没有结果集指针）。在这种情况下，您可以调用mysql_field_count()来确定mysql_store_result()是否应该产生非空结果。这使客户端程序能够在不知道查询是SELECT（或类似SELECT）语句的情况下采取适当的操作。
嗯，这似乎准确描述了你案件中出现的情况。在其中链接到Section 23.8.15.1, “Why mysql_store_result() Sometimes Returns NULL After mysql_query() Returns Success”：
成功调用
mysql_store_result()后，mysql_query()可能会返回NULL。发生这种情况时，表示发生以下情况之一：
由于在您执行SELECT查询时出现了这种情况，并且没有任何关于连接错误的迹象（如果那是我想将被客户端删除因此，似乎这个错误的最可能原因是malloc()失败。 This answer可以很好地解释malloc()失败的情况。
有没有办法解决它？
当然有，是的！但它可能涉及详细分析MySQL为什么在这种情况下尝试分配内存失败的原因。我的猜测是你的托管环境限制了MySQL可用的内存，并且已经达到内存分配。
或许只是增加MySQL可用的内存会有帮助吗？否则，您可能希望阅读How MySQL Uses Memory并开始调整一些服务器设置......
是否有可靠的解决方法？
如果出现这种情况，您可能只是简单地重新尝试查询？
答案 1 :(得分：-1)
我已经通过释放我的服务器磁盘空间来解决此问题，因为我的服务器达到了100％的使用率。
此问题已记录在/var/log/mysql/error.log中，因此在执行任何操作之前，我始终先检查错误日志。