比较php中的数组值并更新表

Question

我在 php $resultA 和 $resultB 中有两个来自 SQL 选择语句的数组。该数组是用 mysqli_fetch_array(MYSQLI_ASSOC) 构建的。我想比较每个科目的成绩，或者得到提高、降低或保持不变的结果。比较数组中的这些值并将结果添加到数组末尾的新字段（即 ReadingPerformance、MathPerformance、SciencePerformance 和 AttendancePerformance）的最佳做法是什么，以便可以访问它们以显示在表格中

Array ( [mID] => 1 [mFirst] => Mike [mLast] => Davis [mNumber] => 123456789 [mSchool] => SSAS [mGrade] => 8 [gID] => 0 [gYear] => 2017 [gReading] => A [gMath] => A [gScience] => B [gSemester] => Q1 [gDaysAbsent] => 1 ) 
Array ( [mID] => 1 [mFirst] => Mike [mLast] => Davis [mNumber] => 123456789 [mSchool] => SSAS [mGrade] => 8 [gID] => 1 [gYear] => 2017 [gReading] => B [gMath] => B [gScience] => A [gSemester] => Q2 [gDaysAbsent] => 4 )

最终表格标题

Answer 1

注意：mysqli_fetch_array() 在 PHP7 中已弃用，请考虑将 mysqli 类与 fetch_assoc() 一起使用

我假设您已经订购了您的查询，可能是通过 mID，这将使这种方式更容易。 我的建议是创建一个数组，在其中收集数据，然后循环遍历它以创建表（我将按顺序将其写出，但您应该考虑将其分割成类方法）。注意：这是未经测试的。

// execute the query
$result = mysqli_query($handler, $query);

// create a stack to collect the data
$data = array();

// the table header, will also be used to store values in order
$metaData = array(
    'mID' => 'MemberID(system)',
    'mFirst' => 'First Name',
    // other meta data (make sure you use the field names)...
);

$grades = array(
    'gReading' => 'Reading',
    'gMath' => 'Math',
    'gScience' => 'Science',
    'gDaysAbsent' => 'Absent'
);

// create a table header
$tableHeader = $metaData;
// create 3 fields for each subject
foreach ($grades as $fieldname => $headline) {
    $tableHeader[$fieldname . 'Q2'] = $headline . ' Q2';
    $tableHeader[$fieldname . 'Q1'] = $headline . ' Q1';
    $tableHeader[$fieldname . 'Performance'] = $headline . ' Performance';
}

// read each row of the result
while ($row = mysqli_fetch_array($result, MYSQLI_ASSOC)) {
    // we haven't handled this user before
    if (!array_key_exists($row['mID'], $data)) {
        // create a row with the meta data
        $tableRow = array();
        foreach ($metaData as $fieldname => $headline) {
            $tableRow[$fieldname] = $row[$fieldname];
        }
    } else {
        // fetch this users previous data
        $tableRow = $data[$row['mID']];
    }
    // populate the grades for this quarter and calculate the performance
    foreach ($grades as $gradename => $headline) {
        // f.ex. gReadingQ1
        $tableRow[$gradename . $row['gSemester']] = $row[$gradename];
        // calculate the performance
        if ($tableRow[$gradename . 'Q1'] && $tableRow[$gradename . 'Q2']) {
            // TODO: do some magic here
            // f.ex. calculate the number of the letter in the alphabet and get the average
            $tableRow[$gradename . 'Performance'] = 'SOMETHING';
        }
    }
    // store the row
    $data[$row['mID']] = $tableRow;
}

// TODO: create the table in whatever format you want
print_r($data);