mysql - how to select random unique records on each execution of the SQL Query

Question

I have a table "masterurls" it has morethan 1 million records. I want to fetch random records each time the query executed. It should not have any of the records that were fetched in previous executions. I'm already have this query:

SELECT m.url FROM masterurls ORDER BY RAND() LIMIT 200

The problem is the above query returns only first 200 hundred records and randomizes it each time.

Answer 1

How are you going to know if the url is already accessed before. My best suggestion would be setting a flag to know this in the table. Add a field like view in the table which will accept two values 1 or 0, 1 for already accessed and 0 for not accessed. Then you could use

SELECT m.url FROM masterurls m WHERE view='1' ORDER BY RAND() LIMIT 200;