Question

select student.student_fname,
student.student_mname,
student.student_lname, logs.time, logs.transaction,logs.entity_type,prof.professor_fname,prof.professor_mname,prof.professor_lname 
from student_tbl as student,
logs_tbl as logs,
professor_tbl as prof 
where student.student_id=logs.entity_id 
and prof.professor_id=logs.entity_id
and logs.date ='$date_today' 
and logs.course_id='$course' 
and logs.sections_id='$sections'
and logs.rooms_id='$room'  
group by logs.date, 
logs.term, 
logs.course_id, 
logs.entity_id  
order by logs.logs_id asc

在student_tbl和professor_tbl中，我的student_id和professor_id等于logs_tbl的entity_id。我如何将不同表中的两个id与logs_tbl中的entity_id进行比较？这是唯一给我错误的一条线。或者你有建议吗？除了sql注入的东西

更新

我有 student_tbl 列：student_id，student_fname，student_mname，student_lname。我也有教授_tbl，其中有以下列： professor_id ，professor_fname，professor_mname，professor_lname和我的第三个表，它的所有基础是 logs_tbl 列：entity_id （这是student_id和professor_id将等同的地方），course_id，rooms_id，sections_id，time，date，transaction，entity_type。这就是我想要展示的内容：

student_fname / professor_fname（取决于entity_id）
student_mname / professor_mname（取决于entity_id）
student_lname / professor_lname（取决于entity_id）
时间
交易
ENTITY_TYPE

示例数据显示：

Kris | Consta |罗卡| 11:30 |在|学生
鲍勃|琼斯|马利| 11:32 |在|学生
罗纳德|詹姆斯|莱昂| 11:35 |在|教授
- Kris | Consta |罗卡| 1:00 |出|学生
鲍勃|琼斯|马利| 1:05 |出|学生
罗纳德|詹姆斯|莱昂| 1:06 |出|教授

Answer 1

  select student.student_fname,  student.student_mname, student.student_lname, logs.time, logs.transaction,logs.entity_type
          from student_tbl as student inner join logs_tbl as logs on student.student_id=logs.entity_id  
     where   logs.date ='$date_today' 
                and logs.course_id='$course' 
                and logs.sections_id='$sections'
                and logs.rooms_id='$room'  
                group by logs.date,  logs.term, 
                logs.course_id, 
                logs.entity_id   


    UNION  

      select prof.professor_fname,prof.professor_mname,prof.professor_lname , logs.time, logs.transaction,logs.entity_type
          from   professor_tbl as prof inner join logs_tbl as logs   on prof.professor_id=logs.entity_id
             where   logs.date ='$date_today' 
                and logs.course_id='$course' 
                and logs.sections_id='$sections'
                and logs.rooms_id='$room'  
                group by logs.date,  logs.term, 
                logs.course_id, 
                logs.entity_id

Answer 2

select student.student_fname,student.student_mname,student.student_lname, logs.time, logs.transaction,logs.entity_type,prof.professor_fname,prof.professor_mname,prof.professor_lname 
from student_tbl as student
join logs_tbl as logs on student.student_id=logs.entity_id and logs.date ='$date_today' and logs.course_id='$course' and logs.sections_id='$sections' and logs.rooms_id='$room'
join professor_tbl as prof on prof.professor_id=logs.entity_id
group by logs.date, logs.term, logs.course_id, logs.entity_id 
order by logs.logs_id asc

您可以使用join。

如何从另一个表中等于两个不同的ID？

2 个答案: