Question

Is it possible to retrieve random rows from table X where flags==0?
Using MySql and C#

Answer 1

SELECT *
FROM X
WHERE flags = 0
ORDER BY rand()
LIMIT 1

This retrieves 1 random row. Replace 1 by N to get N random rows.

Caveat: As others pointed out this can be slow as it needs a full table scan. I used to do this with DB2, where this worked perfectly for tables with hundreds of thousand of rows, but according to the link in tereško’s answer, MySQL seems to degrade much quicker.