我的表是:
studens_exam_answers_tbl
----------------------------------------------------
exam_id | question_id | student_id | student_answer
----------------------------------------------------
10 1 6 1
10 2 6 4
10 3 6 3
10 4 6 0
10 5 6 5
10 1 5 1
10 2 5 2
10 3 5 2
10 4 5 5
10 5 5 5
question_poll__tbl
--------------------------------------------------------------------------------
question_id | question | option_1 | option_2 | ....| option_5 |correct_answer
--------------------------------------------------------------------------------
1 .... .... .... ... .... 5
2 .... .... .... ... .... 2
3 .... .... .... ... .... 3
4 .... .... .... ... .... 4
5 .... .... .... ... .... 1
我想用sql匹配学生答案和正确答案。如果学生回答正确，则“这是真的”，否则为“假”。如果 student_answer 为 0 '空'。
我该怎么做？
最佳答案
试试这个
Select student id, (Case when student_answer=0
then ""
else
when student_answer=correct_answer then "true"
else "false"
end ) as Result
from studens_exam_answers_tbl inner join question_poll__tbl on studens_exam_answers_tbl.question_id.question_id =question_poll__tbl.question_id
关于mysql - php mysql匹配及返回值，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/16032671/