patternsqlMinor
Select random 10 unique rows from MySQL database?
Viewed 0 times
randomuniquerowsdatabasemysqlselectfrom
Problem
I have one table (
The students have to answer all 54 questions.
I have to show 10 questions at once, then next 10 and so on....
I have to select 10 questions randomly and next 10 random questions except the previous 10 questions that already answered, and so on....
I store all the answers in another table named
what will be the MySQL Query?
questions) with 54 questions. The students have to answer all 54 questions.
I have to show 10 questions at once, then next 10 and so on....
I have to select 10 questions randomly and next 10 random questions except the previous 10 questions that already answered, and so on....
I store all the answers in another table named
user_answer.what will be the MySQL Query?
Solution
You can do this by using following query.
I have assumed that there is 3 tables.
I expect that student_id is the primary key of student table and foreign key of student_answer table.
The student_is is brought from session or somewhere.
SELECT * FROM questions WHERE question_id NOT IN (SELECT question_id FROM student_answers WHERE student_id = '5') ORDER BY RAND() LIMIT 10;I have assumed that there is 3 tables.
- question - Hold all questions
- student_answers - hold student specific answers of each question.
- student - hold student informations.
I expect that student_id is the primary key of student table and foreign key of student_answer table.
The student_is is brought from session or somewhere.
Context
StackExchange Database Administrators Q#91685, answer score: 3
Revisions (0)
No revisions yet.