Question

所以我试图发送一个长的附加sql查询，它将填充一个临时表。根据表格，我填充了一个存储表格中不同值的数组。

第一个insert语句运行完全正常，并正确插入到数组中。接下来的两个附加查询似乎没有填充数组。

在做了一些错误检查之后，我已经验证了语句在查询末尾的确具有正确的值。

注意：用户名，密码和数据库已从代码中删除

非常感谢任何和所有帮助。

<?php
session_start();
$servername = "localhost";
$username   = "";
$password   = "";
$db         = "";

$conn       = new mysqli($servername, $username, $password, $db);
if ($conn->connect_error) {
die("Connection failed:" . $conn->connect_error);
}

$courseID = $_GET['id'];
echo $courseID;

$studentID = $_SESSION['memberID'];
echo $studentID;

$maketemp = "CREATE TEMPORARY TABLE IF NOT EXISTS TempCourseProfile (
CourseID int not null,
CourseName varchar(100),
CourseDescription varchar(200),
CourseObjectives varchar(200),
CourseStartDate date,
CourseEndDate date,
InstructorFirstName varchar(50),
InstructorLastName varchar(50),
PRIMARY KEY(CourseID))";

if($conn->query($maketemp) === TRUE){
echo "you win";
} 
else {
echo "you lose";
}

$query = "INSERT INTO TempCourseProfile(CourseID, CourseName, CourseDescription, CourseObjectives)
SELECT CourseID, CourseName, CourseDescription, CourseObjectives FROM Course     WHERE CourseID = $courseID;";

$query .= "INSERT INTO TempCourseProfile(CourseStartDate, CourseEndDate)
Select CI.ClassStartDate, CI.ClassEndDate From CourseInSemester CI JOIN     ClassSchedule CS on CI.CourseInSemesterID = CS.CourseInSemesterID WHERE     CS.StudentID = $studentID AND CI.CourseID = $courseID;";

$query .= "INSERT INTO TempCourseProfile(InstructorFirstName, InstructorLastName)
    Select M.FirstName, M.LastName from Member M JOIN CourseInSemester CI ON CI.TeacherID = M.MemberID JOIN ClassSchedule CS ON CS.CourseInSemesterID = CI.CourseInSemesterID WHERE CI.CourseID = $courseID AND CS.StudentID = $studentID;";

echo $query;
if ($conn->multi_query($query)) {
do{
    echo "added";

}while($conn->next_result());
} else {
echo "failed to create temp" . $conn->error;
}

$tmparray = array();
$sql      = "SELECT * FROM TempCourseProfile where CourseID = $courseID";
//$result   = $conn->query($sql);
if($result = $conn->query($sql)){
while ($r = $result->fetch_array()) {
$e                      = array();
$e['CourseID']          = $r['CourseID'];
$e['CourseName']         = $r['CourseName'];
$e['CourseDescription']          = $r['CourseDescription'];
$e['CourseObjectives']             = $r['CourseObjectives'];
$e['CourseStartDate']         = $r['CourseStartDate'];
$e['CourseEndDate']    = $r['CourseEndDate'];
$e['InstructorFirstName']   = $r['InstructorFirstName'];
$e['InstructorLastName'] = $r['InstructorLastName'];
array_push($tmparray, $e);
}

} else {
echo $conn->error;
}


echo json_encode($tmparray);

?>

问题必须处理$e['CourseStartDate']，$e['CourseEndDate']，$e['InstructorFirstName']，$e['InstructorLastName']

的价值观

Answer 1

不要使用multi_query。逐个运行您的查询。
总是让mysqli报告错误。向人们询问数据库有什么问题是没用的 - 他们无法知道。只有您的数据库可以确定。

所以以这种方式编写代码

$queries = ["CREATE TEMPORARY TABLE IF NOT EXISTS TempCourseProfile (
CourseID int not null,
CourseName varchar(100),
CourseDescription varchar(200),
CourseObjectives varchar(200),
CourseStartDate date,
CourseEndDate date,
InstructorFirstName varchar(50),
InstructorLastName varchar(50),
PRIMARY KEY(CourseID))"];

$queries[] = "INSERT INTO TempCourseProfile(CourseID, CourseName, CourseDescription, CourseObjectives)
SELECT CourseID, CourseName, CourseDescription, CourseObjectives FROM Course     WHERE CourseID = $courseID;";

$queries[] = "INSERT INTO TempCourseProfile(CourseStartDate, CourseEndDate)
Select CI.ClassStartDate, CI.ClassEndDate From CourseInSemester CI JOIN     ClassSchedule CS on CI.CourseInSemesterID = CS.CourseInSemesterID WHERE     CS.StudentID = $studentID AND CI.CourseID = $courseID;";

$queries[] = "INSERT INTO TempCourseProfile(InstructorFirstName, InstructorLastName)
    Select M.FirstName, M.LastName from Member M JOIN CourseInSemester CI ON CI.TeacherID = M.MemberID JOIN ClassSchedule CS ON CS.CourseInSemesterID = CI.CourseInSemesterID WHERE CI.CourseID = $courseID AND CS.StudentID = $studentID;";

foreach ($queries as $query) {
    $conn->query($query) or trigger_error($conn->error);
}

此代码不会回复任何无用的垃圾邮件，但一旦发生就会报告确切的错误。

Answer 2

使用multi_query的原因非常简单。我们要限制与数据库的通信-单个请求比1000个请求一个接一个地快得多。

multi_query的替代方法是单个查询中有多个记录。

INSERT INTO .. (col1, col2) VALUES (v1.1,v2.1), (v1.2, v2.2), (v1.3, v2.3) ...;

但是所有数据中的大多数都应在插入查询之前进行验证。许多面向对象的数据模型都通过缓存表列和类型，根据实际的数据库结构为您完成此操作

DESCRIBE table;

在执行任何查询之前，插入/更新之前的数据会受到特定列类型和格式的损害。

MySQL：多查询不执行第二和第三追加查询

2 个答案: