Question

您好，我在分配课程时都尝试获取特定课程的截止日期，因此我有3种类型的表，可以在这3个表中为用户分配课程，而我有userid列，因此在我的课程表中必须满足条件，但如果我仅给出一个条件，则它不起作用

这是我的查询：

 $sql1="SELECT cm.id as cmid,c.id as cid,c.fullname,c.startdate,c.timecreated,c.theme,cm.instance,asg.duedate,asd.duedate,sca.duedate FROM mdl_course c LEFT JOIN mdl_course_modules cm ON c.id=cm.course LEFT JOIN mdl_ppc_assigncourses_group asg On asg.courseid=c.id LEFT JOIN mdl_ppc_assigncourses_dep asd On asd.courseid=c.id LEFT JOIN mdl_ppc_singlecourse_assign sca On sca.courseid=c.id where c.category != 0 and requested='0' AND cm.id!='' AND asg.userid='2101'  and sca.userid= '2101' and asd.userid= '2101' GROUP BY cm.id HAVING COUNT(*) > 0";

在该查询中，如果我仅保留一种where c.category != 0 and requested='0' AND cm.id!='' AND asg.userid='2101'这样的条件，则它正在获取一门课程，我也具有课程形式asg.userid，因此如果我添加它则不起作用

我正在尝试获取该特定课程的截止日期，但对于第一门课程，我得到的第二个截止日期的正确截止日期显示为默认日期（1970-01-01）

这是我的代码：

 <?php
            require_once($CFG->dirroot . '/mod/scorm/lib.php');
            require_once($CFG->dirroot . '/mod/scorm/locallib.php');
            require_once($CFG->dirroot . '/course/lib.php');
            global $DB;
            $id = $USER->id;

            $stmt = $DB->get_records_sql("
                         SELECT asg.asgid,asg.courseid,asg.groupid,asg.duedate FROM mdl_ppc_assigncourses_group asg 
                         JOIN mdl_ppc_group_users pgu ON asg.groupid = pgu.group_id
                         WHERE pgu.userid = '$id' AND asg.status='1'and  pgu.status='1'
                          UNION  SELECT asd.acdid,asd.courseid,asd.depid,asd.duedate FROM mdl_ppc_assigncourses_dep asd 
                         JOIN mdl_ppc_dep_user pdu ON asd.depid = pdu.department 
                         WHERE pdu.userid = '$id' AND asd.status='1' and pdu.status='1'
                         UNION SELECT mpsa.scid,mpsa.courseid,mpsa.depid,mpsa.duedate FROM mdl_ppc_singlecourse_assign mpsa LEFT JOIN mdl_course c ON mpsa.courseid=c.id where mpsa.userid = '$id' and mpsa.status='1'");


            $cids = '';
            foreach ($stmt as $value) {
                $cids[] = $value->courseid;

            }
            //print_r($cids);

           $sql1="SELECT cm.id as cmid,c.id as cid,c.fullname,c.startdate ,c.timecreated ,c.theme ,cm.instance,asg.duedate ,asd.duedate ,sca.duedate 
    FROM mdl_course c 
    LEFT JOIN mdl_course_modules cm ON c.id=cm.course  AND cm.id!=''
    LEFT JOIN mdl_ppc_assigncourses_group asg On asg.courseid=c.id  AND asg.userid='2101'
    LEFT JOIN mdl_ppc_assigncourses_dep asd On asd.courseid=c.id and asd.userid= '2101' 
    LEFT JOIN mdl_ppc_singlecourse_assign sca On sca.courseid=c.id  and sca.userid= '2101'
    where c.category != 0 and requested='0' 
    GROUP BY cm.id 
    HAVING COUNT(*) > 0";
            if ($cids != '') {
                $cids = implode(',', $cids);
                $sql1 .= " and cid in ($cids)";
            }

            $courses = $DB->get_records_sql($sql1);

            if (sizeof($courses) && $cids != '') {
                foreach ($courses as $row) {
                          echo $row->duedate;

                }
            }

有人可以帮我解决吗

谢谢。

Answer 1

如果将where子句用于过滤左连接表列，则此操作将用作内部连接..

您应在子句的相关左联接中移动这些条件

$sql1="SELECT cm.id as cmid
        ,c.id as cid
        ,c.fullname
        ,c.startdate
        ,c.timecreated
        ,c.theme
        ,cm.instance
        ,asg.duedate
        ,asd.duedate
        ,sca.duedate 
        FROM mdl_course c 
        LEFT JOIN mdl_course_modules cm ON c.id=cm.course  AND cm.id!=''
        LEFT JOIN mdl_ppc_assigncourses_group asg On asg.courseid=c.id  AND asg.userid='2101'
        LEFT JOIN mdl_ppc_assigncourses_dep asd On asd.courseid=c.id and asd.userid= '2101' 
        LEFT JOIN mdl_ppc_singlecourse_assign sca On sca.courseid=c.id  and sca.userid= '2101
        where c.category != 0 and requested='0' ' 
        GROUP BY cm.id 
        HAVING COUNT(*) > 0";

MySQL查询条件条件与或在PHP

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