Question

我将相同的2个查询应用于3个表，因此只需循环并替换表名。第一个INSERT查询始终适用于测试服务器和生产。第二个DELETE查询适用于两个不同的测试服务器，但是在生产失败并抛出mysql错误1046没有选择数据库。

受影响的代码提取：

    $queries = array(
        "INSERT INTO knd_bkg.@table@
            SELECT DISTINCT SQL_NO_CACHE
            B.ASIN, Author, Title, EditorialReview, DetailPageURL, current_price, salesrank, number_reviews, erotica, G.BrowseNodeId, price_salesrank_checked_on
            FROM bkd_books.club_books B
            USE INDEX (free_quality)
            RIGHT JOIN bkd_books.book_genre G on G.ASIN=B.ASIN
            WHERE EXISTS
            (
              SELECT 1 FROM knd_bkg.genres K WHERE K.browsenode=G.BrowseNodeId
            )
            AND @priceWhere@
            AND price_salesrank_checked_on > '@newerThan@'
            AND B.number_reviews >= 4
            AND B.rating >= 4.0
            AND B.language = 'english'
            AND B.hide_knd=0
            AND B.public_domain=0;",
        "DELETE T FROM knd_bkg.@table@ T
         INNER JOIN
         (
             SELECT N.* FROM knd_bkg.@table@ N
             INNER JOIN
             (
                 SELECT DISTINCT ASIN, BrowseNodeId FROM knd_bkg.@table@
                 INNER JOIN knd_bkg.genres ON knd_bkg.genres.browsenode=knd_bkg.@table@.BrowseNodeId
                 WHERE isFiction=1
             ) F
             ON F.ASIN=N.ASIN
             INNER JOIN knd_bkg.genres
             ON knd_bkg.genres.browsenode=N.BrowseNodeId
             WHERE knd_bkg.genres.isNonFiction=1
         ) D
         USING (ASIN, BrowseNodeId)
         WHERE D.ASIN=T.ASIN AND D.BrowseNodeId=T.BrowseNodeId"
    );

    $tables = array(
        "free_books" => array('priceWhere' => "B.current_price = 0", 'timePeriod' => $freeTimePeriod),
        "99_books" => array('priceWhere' => "B.current_price > 0 AND B.current_price < 100", 'timePeriod' => $paidTimePeriod),
        "399_books" => array('priceWhere' => "B.current_price >= 100 AND B.current_price < 400", 'timePeriod' => $paidTimePeriod),
    );

    connectSlaveDB();

    foreach ($tables as $table => $data) {
        $newerThan = date("Y-m-d H:i:s", strtotime("-" . $data['timePeriod'] . " hours"));
        foreach ($queries as $query) {
            $query = str_replace('@table@', $table, $query);
            $query = str_replace('@newerThan@', $newerThan, $query);
            $query = str_replace('@priceWhere@', $data['priceWhere'], $query);
            Logger::_write(LOG_VERBOSE, "API - api/bkg/rebuild query: $query");
            $result = mysql_query($query);
            if (!$result) {
                Logger::_write(LOG_ERR, "API - api/bkg/rebuild FAILED: " . mysql_error());
                $success = false;
            } else {
                Logger::_write(LOG_VERBOSE, "API - api/bkg/rebuild SUCCESS");
            }
        }
    }

和connectSlaveDB（）

function connectSlaveDB()
{
    global $dbSlave, $dbUser, $dbPass, $dbName;
    $connSlave = mysql_connect($dbSlave, $dbUser, $dbPass, TRUE);
    if (!$connSlave) {
        Logger::_write(LOG_CRIT, "Unable to connect to slave DB");
        include 'screens/error.inc.php';
        exit();
   }
    mysql_set_charset('utf8', $connSlave);
    mysql_select_db($dbName, $connSlave);
    return TRUE;
}

这些表是MEMORY表，但我在MYISAM中遇到了同样的错误，并且仅在生产时出现错误。此查询在复制从属服务器上运行，并且不涉及主服务器，但是之前的代码会对表进行TRUNCATES，因此我不认为这取决于权限。当从日志文件中取出查询时，它在phpMyAdmin中正常工作。它在测试服务器上很好用。

我没有得到1046 No database selected错误的原因。 3个小时后，我可能会遗漏一些非常明显的东西。特别是因为故障模式是这样的，对于一个DB连接：

INSERT on free_books - success
DELETE on free_books - fail
INSERT on 99_books - success
DELETE on 99_books - fail
INSERT on 399_books - success
DELETE on 399_books - fail

请原谅丑陋的全局和弃用的mysql *函数。这是一个过时的遗留应用程序。我知道......

Answer 1

看起来DELETE中的T别名导致了问题，但我不确定为什么。现在通过使DELETE查询为：

来解决该问题

"DELETE knd_bkg.@table@ FROM knd_bkg.@table@
     INNER JOIN
     (
         SELECT N.* FROM knd_bkg.@table@ N
         INNER JOIN
         (
             SELECT DISTINCT ASIN, BrowseNodeId FROM knd_bkg.@table@
             INNER JOIN knd_bkg.genres ON knd_bkg.genres.browsenode=knd_bkg.@table@.BrowseNodeId
             WHERE isFiction=1
         ) F
         ON F.ASIN=N.ASIN
         INNER JOIN knd_bkg.genres
         ON knd_bkg.genres.browsenode=N.BrowseNodeId
         WHERE knd_bkg.genres.isNonFiction=1
     ) D
     USING (ASIN, BrowseNodeId)
     WHERE D.ASIN=knd_bkg.@table@.ASIN AND D.BrowseNodeId=knd_bkg.@table@.BrowseNodeId"

Answer 2

DELETE查询的语法可能导致问题

DELETE T FROM

我知道由于mysql错误，这有时会导致UPDATE查询出现问题。

重写您的查询以避免T引用应解决此问题。

在循环中，某些查询成功，其他查询失败“未选择数据库”

2 个答案: