im having a problem regrading a query which will update earning table with another random value from users table. when executing the query it do nothing
$update = mysql_query("UPDATE earnings SET userid = (SELECT ID FROM users WHERE installid is NULL ORDER BY rand()) WHERE userid='0'");
in the second query
SELECT ID FROM users WHERE installid is NULL ORDER BY rand()
it will get me a random userid where installid null
Have you tried that query in phpMyAdmin etc? Are you getting an error?
Have you tried:
SELECT ID FROM users WHERE installid is NULL ORDER BY rand() LIMIT 1
So that the full query becomes:
UPDATE earnings SET userid = (SELECT ID FROM users WHERE installid is NULL ORDER BY rand() LIMIT 1) WHERE userid='0'
However keep in mind that you may end up having duplicate userid values in the earnings table.
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