PHP/SQL: Using only one query, SELECT rows from two tables if data is in both tables, or just SELECT from one table if not
I have two rating/votes tables. One for user votes and stats and another for external votes. The external votes table always have data because it has a DEAFULT = 0, but the users votes only contains data if any user have voted for that specific ID.
So I do something like this:
$sql = 'SELECT ratings_stats.votes, ratings_stats.total_value,
ratings_stats.view, ratings_stats.fav, ratings_stats.wish,
ratings_external.votes, ratings_external.total_value
FROM ratings_stats, ratings_external
WHERE ratings_stats.imdbID = ?
AND ratings_stats.imdbID = ratings_external.imdbID
LIMIT 1';
I want to select data from both tables if available OR only form the second (external votes) table if not.
How to can I do it without making a new query开发者_运维知识库?
SELECT ratings_stats.votes,
ratings_stats.total_value,
ratings_stats.view,
ratings_stats.fav,
ratings_stats.wish,
ratings_external.votes,
ratings_external.total_value
FROM ratings_external
LEFT JOIN ratings_stats ON ratings_stats.imdbID = ratings_external.imdbID
WHERE ratings_external.imdbID = ?
LIMIT 1
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