Accessing random rows from database without repetition

问题

I have designed a quiz scenario using MySQL database as my backend.

I have a total of 20 questions and I would want to display them in random order from the database. I have tried :

SELECT * from mst_que ORDER BY RAND();

What the above query does is repeat few rows.

回答1:

If the table contains duplicate records, use SELECT DISTINCT to filter them out.

SELECT DISTINCT *
FROM mst_que
ORDER BY RAND()

回答2:

The order by clausule needs column names or relative positions , not values or values. So. Try to add the RAND to the select and order by it. Try this:

SELECT *, RAND() as ordering
FROM mst_que
ORDER by ordering;

来源：https://stackoverflow.com/questions/49655053/accessing-random-rows-from-database-without-repetition