使用sql查询结果作为新sql语句的搜索项 - Using an sql query result as a search term for a new sql statement

Using an sql query result as a search term for a new sql statement

所以我尝试使用SQL搜索$search_course的结果，然后将其作为下一个语句$Search_Module的WHERE LIKE部分。

一旦$Search_Module查询完成，我希望结果在一个我知道应该正确编码的列表中。

我尝试了以下代码，但搜索没有返回任何值；

如有任何帮助，我们将不胜感激，并提前表示感谢。

        $search_course = "
    SELECT title, id, wyl, overview, module, course, careers
    FROM course
    LEFT JOIN cm
    ON course.id=cm.course
    WHERE id LIKE '%".$_POST['submitcourseselection']."%'";
    $result = $mysqli->query($search_course) or die($mysqli->error);
    $display_course = $result->fetch_assoc();
    //Searches the module table in the DB for modules within the course
    $Search_Module = "
    SELECT id, title, level, credits
    FROM module
    WHERE id LIKE '".$search_course['module']."'";
    $M_Results = $mysqli->query($Search_Module) or die($mysqli->error);

    $ModuleList = '';
    while ($MResults = $M_Results->fetch_assoc()) {
        $ID = $MResults['id'];
        $Title = $MResults['title'];
        $Level = $MResults['level'];
        $Credits = $MResults['credits'];
        $ModuleList.='<div><h2>'.$Title.'</h2></div>'; 
    }

在第二个查询中不需要LIKE，您可以通过一个查询完成所有查询。

    $search_course = "
        SELECT id, title, level, credits
        FROM module
        WHERE id IN (SELECT module
        FROM course
        LEFT JOIN cm
        ON course.id=cm.course
        WHERE id LIKE '%".$_POST['submitcourseselection']."%'")";

在where子句WHERE id LIKE '".$search_course['module']."'";中，您正在引用字符串$search_course的数组位置，这是您的SQL语句。

我想你是想引用你的结果数组$display_course，所以试试这个：

$search_course = "
SELECT title, id, wyl, overview, module, course, careers
FROM course
LEFT JOIN cm
ON course.id=cm.course
WHERE id LIKE '%".$_POST['submitcourseselection']."%'";
$result = $mysqli->query($search_course) or die($mysqli->error);
$display_course = $result->fetch_assoc();
//Searches the module table in the DB for modules within the course
$Search_Module = "
SELECT id, title, level, credits
FROM module
WHERE id LIKE '".$display_course['module']."'";
$M_Results = $mysqli->query($Search_Module) or die($mysqli->error);

$ModuleList = '';
while ($MResults = $M_Results->fetch_assoc()) {
    $ID = $MResults['id'];
    $Title = $MResults['title'];
    $Level = $MResults['level'];
    $Credits = $MResults['credits'];
    $ModuleList.='<div><h2>'.$Title.'</h2></div>'; 
}