循环的PHP性能问题

我使用PHP执行SQL查询，然后为一群用户提取时间表数据。 早些时候，它运行得相当快，但现在由于用户和任务数量的增加，速度急剧放缓。 我已经使用了很多while，用于循环。不确定我可以优化什么，因为计算是迭代的。 如果有人能看一下代码并提出一些建议，我将不胜感激

private function processGETUSERTIMEREPORTDATA(SimpleXMLElement $xml, DBHandler $dbh) {
        $from = Utils::convertToDatetime($this->clientDateFormat, $xml->FROM);
        $to = Utils::convertToDatetime($this->clientDateFormat, $xml->TO);
        $usercode = stripslashes(html_entity_decode($xml->UNCODE));
        $this->logger->LogDebug("User List: " . $usercode);
        $userArr = json_decode($usercode, TRUE);
        $tChgMode = $xml->TASKCHGMODE;
        $tType = $xml->TASKTYPE;
        $timeSheetCategory = $xml->TIMESHEETCAT;

        $totalChgHrsArr = array();
        $totalNonChgHrsArr = array();
        $totalGenNonChgHrsArr = array();
        $totalChgDaysArr = array();
        $totalDaysALeaveArr = array();
        $totalDaysSLeaveArr = array();
        $totalDaysCLeaveArr = array();
        $totalExpensesArr = array();

        // Set timesheet category table
        if ($timeSheetCategory == "ALL") {
            $tablename = array("tblChargeHours", "tblNonChargeHours", "tblFieldDays",
                "tblNonChargeDays", "tblExpensesSheet", "tblGeneralNonChargeHours");
        } else if ($timeSheetCategory == "Chargeable Hours") {
            $tablename = array("tblChargeHours");
        } else if ($timeSheetCategory == "Non Chargeable Hours") {
            $tablename = array("tblNonChargeHours");
        } else if ($timeSheetCategory == "Chargeable Days") {
            $tablename = array("tblFieldDays");
        } else if ($timeSheetCategory == "Leaves") {
            $tablename = array("tblNonChargeDays");
        } else if ($timeSheetCategory == "Expenses") {
            $tablename = array("tblExpensesSheet");
        } else if ($timeSheetCategory == "General Non Chargeable Hours") {
            $tablename = array("tblGeneralNonChargeHours");
        }
        $arrlength = count($tablename);
        $userCount = count($userArr);

        for ($i = 0; $i < $userCount; $i++) {
            for ($x = 0; $x < $arrlength; $x++) {
                // Leaves table
                if ($tablename[$x] == "tblNonChargeDays") {

                    // Annual Leave
                    $daysSum = 0;
                    $query = "SELECT Mo, Tu, We, Th, Fr, Sa, Su from " . $tablename[$x] . " WHERE (WeekEnding BETWEEN '$from' AND '$to') AND (TaskCode='1') AND (NameCode='" . $userArr[$i] . "')";
                    $hoursRes = $dbh->executeQuery($query);

                    if ($dbh->getQueryStatus()) {
                        while ($timerow = mysqli_fetch_assoc($hoursRes)) {
                            $daysSum += ($timerow['Mo'] + $timerow['Tu'] + $timerow['We'] + $timerow['Th'] + $timerow['Fr'] + $timerow['Sa'] + $timerow['Su']);
                        }
                        $totalDaysALeaveArr[] = $daysSum;
                    } else {
                        $this->logger->LogError("Unable to generate Timesheet report data. Q : " . $query . " E : " . $dbh->getQueryMessage());
                        return ResponseGenerator::generateNegativeRepsonse($this->reqName, "Unable to generate Timesheet report data. Q : " . $query . " E : " . $dbh->getQueryMessage());
                    }

                    // Sick Leave
                    $daysSum = 0;
                    $query = "SELECT Mo, Tu, We, Th, Fr, Sa, Su from " . $tablename[$x] . " WHERE (WeekEnding BETWEEN '$from' AND '$to') AND (TaskCode='2') AND (NameCode='" . $userArr[$i] . "')";
                    $hoursRes = $dbh->executeQuery($query);

                    if ($dbh->getQueryStatus()) {
                        while ($timerow = mysqli_fetch_assoc($hoursRes)) {
                            $daysSum += ($timerow['Mo'] + $timerow['Tu'] + $timerow['We'] + $timerow['Th'] + $timerow['Fr'] + $timerow['Sa'] + $timerow['Su']);
                        }
                        $totalDaysSLeaveArr[] = $daysSum;
                    } else {
                        $this->logger->LogError("Unable to generate Timesheet report data. Q : " . $query . " E : " . $dbh->getQueryMessage());
                        return ResponseGenerator::generateNegativeRepsonse($this->reqName, "Unable to generate Timesheet report data. Q : " . $query . " E : " . $dbh->getQueryMessage());
                    }

                    // Compassionate Leave
                    $daysSum = 0;
                    $query = "SELECT Mo, Tu, We, Th, Fr, Sa, Su from " . $tablename[$x] . " WHERE (WeekEnding BETWEEN '$from' AND '$to') AND (TaskCode='3') AND (NameCode='" . $userArr[$i] . "')";
                    $hoursRes = $dbh->executeQuery($query);

                    if ($dbh->getQueryStatus()) {
                        while ($timerow = mysqli_fetch_assoc($hoursRes)) {
                            $daysSum += ($timerow['Mo'] + $timerow['Tu'] + $timerow['We'] + $timerow['Th'] + $timerow['Fr'] + $timerow['Sa'] + $timerow['Su']);
                        }
                        $totalDaysCLeaveArr[] = $daysSum;
                    } else {
                        $this->logger->LogError("Unable to generate Timesheet report data. Q : " . $query . " E : " . $dbh->getQueryMessage());
                        return ResponseGenerator::generateNegativeRepsonse($this->reqName, "Unable to generate Timesheet report data. Q : " . $query . " E : " . $dbh->getQueryMessage());
                    }

                    // GeneralNonChgHours Table 
                } else if ($tablename[$x] == "tblGeneralNonChargeHours") {

                    $hoursSum = 0;
                    $query = "SELECT Mo, Tu, We, Th, Fr, Sa, Su from " . $tablename[$x] . " WHERE (WeekEnding BETWEEN '$from' AND '$to') AND (NameCode='" . $userArr[$i] . "')";
                    $hoursRes = $dbh->executeQuery($query);

                    if ($dbh->getQueryStatus()) {
                        while ($timerow = mysqli_fetch_assoc($hoursRes)) {
                            $hoursSum += ($timerow['Mo'] + $timerow['Tu'] + $timerow['We'] + $timerow['Th'] + $timerow['Fr'] + $timerow['Sa'] + $timerow['Su']);
                        }
                        $totalGenNonChgHrsArr[] = $hoursSum;
                    } else {
                        $this->logger->LogError("Unable to generate Timesheet report data. Q : " . $query . " E : " . $dbh->getQueryMessage());
                        return ResponseGenerator::generateNegativeRepsonse($this->reqName, "Unable to generate Timesheet report data. Q : " . $query . " E : " . $dbh->getQueryMessage());
                    }
                }
            }   // end-for-tablename
        }   // end-for-usercode

        if ($tChgMode == "ALL") {
            if ($tType == "ALL") {
                // $tChgMode = ALL && $tType = ALL
                $tquery = "SELECT TCode, TType FROM tblTasks WHERE (TCreatedDate BETWEEN '$from' AND '$to')";
            } else {
                // $tChgMode = ALL && $tType = Sel
                $tquery = "SELECT TCode, TType FROM tblTasks WHERE (TCreatedDate BETWEEN '$from' AND '$to') AND (TType='" . $tType . "') ORDER BY TCode ASC";
            }
        } else {
            if ($tType == "ALL") {
                // $tChgMode = Sel && $tType = ALL
                $tquery = "SELECT TCode, TType FROM tblTasks WHERE (TCreatedDate BETWEEN '$from' AND '$to') AND (TChargeMode='" . $tChgMode . "') ORDER BY TCode ASC";
            } else {
                // $tChgMode = Sel && $tType = Sel
                $tquery = "SELECT TCode, TType FROM tblTasks WHERE (TCreatedDate BETWEEN '$from' AND '$to') AND (TChargeMode='" . $tChgMode . "') AND (TType='" . $tType . "') ORDER BY TCode ASC";
            }
        }

        $result = $dbh->executeQuery($tquery);
        $tqueryArr = array();       // Store the query results
        while ($row = mysqli_fetch_assoc($result)) {
            $tqueryArr[] = $row;
        }

        for ($i = 0; $i < $userCount; $i++) {
            $totalExpenses = 0;
            $totalChgHrs = 0;
            $totalNonChgHrs = 0;
            $totalChgDays = 0;

            foreach ($tqueryArr as $row) {
                for ($x = 0; $x < $arrlength; $x++) {
                    $tCode = $row['TCode'];

                    // Expenses Table
                    if ($tablename[$x] == "tblExpensesSheet") {
                        $query = "SELECT FinalAmount from " . $tablename[$x] . " WHERE (WeekEnding BETWEEN '$from' AND '$to') AND (TaskCode='" . $tCode . "') AND (NameCode='" . $userArr[$i] . "')";
//                        $this->logger->LogDebug($query);
                        $hoursRes = $dbh->executeQuery($query);

                        if ($dbh->getQueryStatus()) {
                            while ($exprow = mysqli_fetch_assoc($hoursRes)) {
                                $totalExpenses += $exprow['FinalAmount'];
                            }
                        } else {
                            $this->logger->LogError("Unable to generate Timesheet report data. Q : " . $query . " E : " . $dbh->getQueryMessage());
                            return ResponseGenerator::generateNegativeRepsonse($this->reqName, "Unable to generate Timesheet report data. Q : " . $query . " E : " . $dbh->getQueryMessage());
                        }

                        // Other Tables
                    } else {
                        $query = "SELECT Mo, Tu, We, Th, Fr, Sa, Su from " . $tablename[$x] . " WHERE (WeekEnding BETWEEN '$from' AND '$to') AND (TaskCode='" . $tCode . "') AND (NameCode='" . $userArr[$i] . "')";
                        $hoursRes = $dbh->executeQuery($query);

                        $totalHours = 0;

                        if ($dbh->getQueryStatus()) {
                            while ($timerow = mysqli_fetch_assoc($hoursRes)) {
                                $hoursSum = ($timerow['Mo'] + $timerow['Tu'] + $timerow['We'] + $timerow['Th'] + $timerow['Fr'] + $timerow['Sa'] + $timerow['Su']);
                                $totalHours += $hoursSum;
                            }
                            switch ($tablename[$x]) {
                                case "tblChargeHours":
                                    $totalChgHrs += $totalHours;
                                    break;
                                case "tblNonChargeHours":
                                    $totalNonChgHrs += $totalHours;
                                    break;
                                case "tblFieldDays":
                                    $totalChgDays += $totalHours;
                                    break;
                                default:
                            }
                        } else {
                            $this->logger->LogError("Unable to generate Timesheet report data. Q : " . $query . " E : " . $dbh->getQueryMessage());
                            return ResponseGenerator::generateNegativeRepsonse($this->reqName, "Unable to generate Timesheet report data. Q : " . $query . " E : " . $dbh->getQueryMessage());
                        }
                    }
                }   // end-for
            }   // end-while
            $totalExpensesArr[] = $totalExpenses;
            $totalChgHrsArr[] = $totalChgHrs;
            $totalNonChgHrsArr[] = $totalNonChgHrs;
            $totalChgDaysArr[] = $totalChgDays;
        }   // end-for-usercode

        $xmlop = new SimpleXMLElement('<RESPONSE/>');
        $xmlop->addChild("REQUESTNAME", $this->reqName);
        $xmlop->addChild("REQUESTSTATUS", "SUCCESS");
        $rowxml = $xmlop->addChild("ROW");

        $rowxml->addChild("USERCODE", json_encode($userArr));
        $rowxml->addChild("CHGHOURS", json_encode($totalChgHrsArr));
        $rowxml->addChild("NONCHGHOURS", json_encode($totalNonChgHrsArr));
        $rowxml->addChild("GENNONCHGHOURS", json_encode($totalGenNonChgHrsArr));
        $rowxml->addChild("FIELDDAYS", json_encode($totalChgDaysArr));
        $rowxml->addChild("ANNLEAVE", json_encode($totalDaysALeaveArr));
        $rowxml->addChild("SICKLEAVE", json_encode($totalDaysSLeaveArr));
        $rowxml->addChild("COMPLEAVE", json_encode($totalDaysCLeaveArr));
        $rowxml->addChild("EXPENSES", json_encode($totalExpensesArr));
        return $xmlop->asXML();
    }

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除了复杂的代码，您可能会发现您有一个索引或缺乏问题

查找任何WHERE子句中使用的每个字段，并为其创建索引

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很有可能，如果您有一个不断增长且逐渐变慢的数据库，这可能是一个索引问题。

我看到重复使用代码、不使用自定义函数、非规范化的数据库方案、错误的变量名以及难以读取的代码。我会投票赞成完全重新设计。你用不同的标准反复询问$tablename[$x]，这是一个大问题。您应该从表中读取记录，并根据任务代码类型等对其进行处理。