Question

i want to select a single record using from two tables. But if you use SIMPLE JOIN, it will only returns the value when the condition satisfies both the table and when we use LEFT or RIGHT JOIN also, it will return all the values from the LEFT or RIGHT table.

I’m using the following query,

SELECT *
FROM activity_feeds
LEFT OUTER JOIN activity_traders ON activity_feeds.feed_id = activity_traders.trdr_feed_id = '11'

I need to get the values from both tables only when activity_feeds.feed_id = activity_traders.trdr_feed_id = '11' and when the value does not matches with the right table, it should return null for the columns in the right table. Please help!

Edit:Table structures added

Feeds

Traders

Answer 1

I assume that all the records are based from activity_feeds whether or not the feed_id exists on activity_traders table as long as it will display all feed_id that has a value of 11. Try this one.

SELECT * 
FROM   activity_feeds a
           LEFT OUTER JOIN  activity_traders b
                ON a.feed_id = b.trdr_feed_id 
WHERE  a.feed_id = '11'