【发布时间】：2013-01-26 02:55:35
【问题描述】：
我有 2 个下拉菜单，用户可以使用下拉菜单过滤他们希望看到的学生和问题。可能的过滤器类型有：
- 选择所有学生和所有问题
- 选择所有学生和一个问题
- 选择所有问题和一名学生
- 选择一名学生和一个问题
以下是下拉菜单：
<p>
<strong>Student:</strong>
<select name="student" id="studentsDrop">
<option value="All">All</option>
<?php
while ( $currentstudentstmt->fetch() ) {
$stu = $dbStudentId;
if(isset($_POST["student"]) && $stu == $_POST["student"])
echo "<option selected='selected' value='$stu'>" . $dbStudentAlias . " - " . $dbStudentForename . " " . $dbStudentSurname . "</option>" . PHP_EOL;
else
echo "<option value='$stu'>" . $dbStudentAlias . " - " . $dbStudentForename . " " . $dbStudentSurname . "</option>" . PHP_EOL;
}
?>
</select>
</p>
<p>
<strong>Question:</strong>
<select name="question" id="questionsDrop">
<option value="All">All</option>
<?php
while ( $questionsstmt->fetch() ) {
$ques = $dbQuestionId;
if(isset($_POST["question"]) && $ques == $_POST["question"])
echo "<option selected='selected' value='$ques'>" . $dbQuestionNo . "</option>" . PHP_EOL;
else
echo "<option value='$ques'>" . $dbQuestionNo . "</option>" . PHP_EOL;
}
?>
</select>
</p>
现在我想设置一个 mysqli 查询来确定从下拉菜单中选择的学生和问题。
我的问题只是我需要设置 4 个查询来检查我从下拉菜单中提到的 4 种可能性还是有更短的方法？
我必须使用：
if ($_POST['question'] == 'All' && if ($_POST['student'] == 'All'){){
//NO WHERE CLAUSE
if ($_POST['question'] == 'All' && if ($_POST['student'] != 'All'){){
//WHERE CLAUSE FOR FINDING SELECTED STUDENT
if ($_POST['question'] != 'All' && if ($_POST['student'] == 'All'){){
//WHERE CLAUSE FOR FINDING SELECTED QUESTION
if ($_POST['question'] != 'All' && if ($_POST['student'] != 'All'){){
//WHERE CLAUSE FOR FINDING SELECTED QUESTION AND SELECTED STUDENT
更新：
我现在拥有的：
function AssessmentIsSubbmitted()
{
if(isset($_POST['answerSubmit'])) // we have subbmited the first form
{
//QUERY 1: Student details depending on selected student(s)
if ($_POST['student'] == 'All'){
$selectedstudentqry = "
SELECT
StudentAlias, StudentForename, StudentSurname
FROM Student s
INNER JOIN Student_Session ss ON s.StudentId = ss.StudentId
WHERE SessionId = ?
ORDER BY StudentAlias
";
global $mysqli;
$selectedstudentstmt=$mysqli->prepare($selectedstudentqry);
// You only need to call bind_param once
$selectedstudentstmt->bind_param("i",$_POST["session"]);
// get result and assign variables (prefix with db)
$selectedstudentstmt->execute();
$selectedstudentstmt->bind_result($detailsStudentAlias,$detailsStudentForename,$detailsStudentSurname);
$selectedstudentstmt->store_result();
$selectedstudentnum = $selectedstudentstmt->num_rows();
}else{
$selectedstudentqry = "
SELECT
StudentAlias, StudentForename, StudentSurname
FROM
Student
WHERE
(StudentId = ?)
ORDER BY StudentAlias
";
global $mysqli;
$selectedstudentstmt=$mysqli->prepare($selectedstudentqry);
// You only need to call bind_param once
$selectedstudentstmt->bind_param("i",$_POST["student"]);
// get result and assign variables (prefix with db)
$selectedstudentstmt->execute();
$selectedstudentstmt->bind_result($detailsStudentAlias,$detailsStudentForename,$detailsStudentSurname);
$selectedstudentstmt->store_result();
$selectedstudentnum = $selectedstudentstmt->num_rows();
}
//QUERY 2: Question details depending on selected question(s)
if ($_POST['question'] == 'All'){
$selectedquestionqry = " SELECT q.QuestionNo, q.QuestionContent, o.OptionType, q.NoofAnswers, GROUP_CONCAT( DISTINCT Answer
ORDER BY Answer
SEPARATOR ',' ) AS Answer, r.ReplyType, q.QuestionMarks
FROM Question q
LEFT JOIN Answer an ON q.QuestionId = an.QuestionId
LEFT JOIN Reply r ON q.ReplyId = r.ReplyId
LEFT JOIN Option_Table o ON q.OptionId = o.OptionId
WHERE SessionId = ?
GROUP BY q.QuestionId
ORDER BY q.QuestionId";
";
global $mysqli;
$selectedquestionstmt=$mysqli->prepare($selectedquestionqry);
// You only need to call bind_param once
$selectedstudentstmt->bind_param("i",$_POST["session"]);
// get result and assign variables (prefix with db)
$selectedquestionstmt->execute();
$selectedquestionstmt->bind_result($detailsQuestionNo,$detailsQuestionContent,$detailsOptionType,$detailsNoofAnswers,
$detailsAnswer,$detailsReplyType,$detailsQuestionMarks);
$selectedquestionstmt->store_result();
$selectedquestionnum = $selectedquestionstmt->num_rows();
}else{
$selectedquestionqry = "
SELECT q.QuestionNo, q.QuestionContent, o.OptionType, q.NoofAnswers, GROUP_CONCAT( DISTINCT Answer
ORDER BY Answer
SEPARATOR ',' ) AS Answer, r.ReplyType, q.QuestionMarks
FROM Question q
LEFT JOIN Answer an ON q.QuestionId = an.QuestionId
LEFT JOIN Reply r ON q.ReplyId = r.ReplyId
LEFT JOIN Option_Table o ON q.OptionId = o.OptionId
WHERE QuestionId = ?
GROUP BY q.QuestionId
ORDER BY q.QuestionId
";
global $mysqli;
$selectedquestionstmt=$mysqli->prepare($selectedquestionqry);
// You only need to call bind_param once
$selectedquestionstmt->bind_param("i",$_POST["question"]);
// get result and assign variables (prefix with db)
$selectedquestionstmt->execute();
$selectedquestionstmt->bind_result($detailsQuestionNo,$detailsQuestionContent,$detailsOptionType,$detailsNoofAnswers,
$detailsAnswer,$detailsReplyType,$detailsQuestionMarks);
$selectedquestionstmt->store_result();
$selectedquestionnum = $selectedquestionstmt->num_rows();
}
//QUERY 3: Student Answers depending on selected student(s) and selected question(s)
$studentanswerqry = "
SELECT
sa.StudentId, sa.QuestionId, GROUP_CONCAT(DISTINCT StudentAnswer ORDER BY StudentAnswer SEPARATOR ',') AS StudentAnswer, ResponseTime, MouseClick, StudentMark
FROM Student_Answer sa
INNER JOIN Student_Response sr ON sa.StudentId = sr.StudentId
WHERE
(sa.StudentId = ? AND sa.QuestionId = ?)
GROUP BY sa.StudentId, sa.QuestionId
";
global $mysqli;
$studentanswerstmt=$mysqli->prepare($studentanswerqry);
// You only need to call bind_param once
$studentanswerstmt->bind_param("ii",$_POST["student"], $_POST["question"]);
// get result and assign variables (prefix with db)
$studentanswerstmt->execute();
$studentanswerstmt->bind_result($detailsStudentAnswer,$detailsResponseTime,$detailsMouseClick,$detailsStudentMark);
$studentanswerstmt->store_result();
$studentanswernum = $studentanswerstmt->num_rows();
}
?>
【问题讨论】：